Nanobiosensors are biosensors on the nano-scale that use biological recognition elements connected to nanoscale transducers. They can detect analytes using techniques like optical measurements, electrochemical methods, electrical sensors like field effect transistors, and nanowires. Nanobiosensors have applications in detecting DNA, proteins, cells, and more for uses in healthcare, environmental monitoring, and other areas due to their high sensitivity and selectivity at the nano-scale level.
A part of nanotechnology. Nanosensors is very hot topic for research. As nanosensor has immense applications in the fields like medical, analysis, research etc. Nanosensor recude the cost and also the time require for analysis.
A Descriptive Review over the field of Biosensors has been given here; its origin history events; its working principle; its classification based on various parameters; applications and future scope
A sensor that integrates a biological element with a physiochemical transducer to produce an electronic signal proportional to a single analyte which is then conveyed to a detector.
The following presentation is only for quick reference. I would advise you to read the theoretical aspects of the respective topic and then use this presentation for your last minute revision. I hope it helps you..!!
Mayur D. Chauhan
The revolution of nanotechnology in molecular biology gives an opportunity to detect and manipulate atoms and molecules at the molecular and cellular level.
Introduction
Definition
History
Advantages of nanobiotechnology
Applications of nanobiotechnology
Drawback of nanobiotechnology
New features in the nanobiotechnology
Conclusion
References
Biosensor is the Talk of The Day. It made possible, the conversion of yesteryear's cumbersome experiments to an easier, faster all the while improving its sensitivity and specificity. This article will help you to gain an acquaintance about it, its properties, etc.
A part of nanotechnology. Nanosensors is very hot topic for research. As nanosensor has immense applications in the fields like medical, analysis, research etc. Nanosensor recude the cost and also the time require for analysis.
A Descriptive Review over the field of Biosensors has been given here; its origin history events; its working principle; its classification based on various parameters; applications and future scope
A sensor that integrates a biological element with a physiochemical transducer to produce an electronic signal proportional to a single analyte which is then conveyed to a detector.
The following presentation is only for quick reference. I would advise you to read the theoretical aspects of the respective topic and then use this presentation for your last minute revision. I hope it helps you..!!
Mayur D. Chauhan
The revolution of nanotechnology in molecular biology gives an opportunity to detect and manipulate atoms and molecules at the molecular and cellular level.
Introduction
Definition
History
Advantages of nanobiotechnology
Applications of nanobiotechnology
Drawback of nanobiotechnology
New features in the nanobiotechnology
Conclusion
References
Biosensor is the Talk of The Day. It made possible, the conversion of yesteryear's cumbersome experiments to an easier, faster all the while improving its sensitivity and specificity. This article will help you to gain an acquaintance about it, its properties, etc.
A sensor that integrates a biological element with a physiochemical transducer to produce an electronic signal proportional to a single analyte which is then conveyed to a detector.
A Biosensor is a device for the detection of an analyte that combines a biological component with a physio-chemical detector component.
Download: https://www.topicsforseminar.com/2014/10/biosensors-ppt.html
biosensor, modern, principles, technology, applications, working of sensor, types of sensor , nanomaterial, based biosensor(nanosensor) optical biosensor, flourescent biosensor, electrochemical and glucose biosensor, genetically encoded biosensor, microbial biosensor, cancer , references included, advantages and disadvantages also included.
Biosensors: General Principles and ApplicationsBhatt Eshfaq
A biosensor is an analytical device, used for the detection of a chemical substance, that combines a biological component with a physicochemical detector.
A scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillating material, and detecting the resultant light pulses or it can be defined as it is used to detect gamma rays and the presence of a particle. It can also measure the radiation in the scintillating medium, the energy loss, or the energy gain. The medium can be solid and liquid.
The phenomenon in which the nucleus of the atom of an element undergoes spontaneous and uncontrollable disintegration or decay and emit alpha, beta, or gamma rays
It is the property of some unstable atoms to spontaneously emit nuclear radiation to gain stability.
The heavy elements are called radioactive elements and rays emitted these elements are called radioactive rays.
The phenomenon of radioactivity is discovered by HENRI BACQUEREL IN 1896.
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay (α-decay), beta decay (β-decay), and gamma decay (γ-decay), all of which involve emitting one or more particles.
Dr.S.Karthikumar
Assistant Professor, Dept. of Biotechnology
Kamaraj College of Engineering and Technology
Madurai, Tamilnadu, INDIA
skarthikumar@gmail.com
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
2. BIOSENSORS
• A device incorporating a biological sensing
element either intimately connected to or
integrated within a transducer.
• Recognition based on affinity between
complementary structures like:
enzyme-substrate, antibody-antigen , receptor-hormone
complex.
• Selectivity and specificity depend on
biological recognition systems connected to
a suitable transducer.
3.
4.
5.
6. Biosensor Development
• 1916 First report on the immobilization of proteins: adsorption of
invertase on activated charcoal.
• 1956 Invention of the first oxygen electrode [Leland Clark]
• 1962 First description of a biosensor: an amperometric enzyme electrode
for glucose. [Leland Clark, New York Academy of Sciences Symposium]
• 1969 First potentiometric biosensor: urease immobilized on an ammonia
electrode to detect urea. [Guilbault and Montalvo]
• 1970 Invention of the Ion-Selective Field-Effect Transistor (ISFET).
• 1972/5 First commercial biosensor: Yellow Springs Instruments glucose
biosensor.
• 1976 First bedside artificial pancreas [Clemens et al.]
• 1980 First fiber optic pH sensor for in vivo blood gases.
• 1982 First fiber optic-based biosensor for glucose
• 1983 First surface plasmon resonance (SPR) immunosensor.
• 1987 Launch of the blood glucose biosensor[ MediSense]
11. 11
Electrical sensing
Nano-bio interfacing how to translate the
biological information onto electrical signal ?
• Electrochemical
– Redox reactions
• Electrical
– FET
(Nano wires; Conducting Electro-active Polymers)
12. 12
Electrical sensors
FET based methods – FET – Field Effect Transistors
ISFET – Ion Sensitive FET
CHEMFET – Chemically Sensitive FET
SAM-FET – Self Assembly Monolayer Based FET
Il principio di funzionamento del transistor a effetto di campo si fonda sulla
possibilità di controllare la conduttività elettrica del dispositivo, e quindi la
corrente elettrica che lo attraversa, mediante la formazione di un campo
elettrico al suo interno.
K Corrente elettrica
Amplificazione di un segnale in
entrata.
Funzionamento da interruttore
(switcher).
13. 13
Nanowires Biosensors
Field Effect
Nanobiosensors (FET)
• Functionalize the nano-wires
• Binding to bio-molecules will affect the nano-wires
conductivity.
14. Nanowire Field Effect Nanobiosensors (FET)
Sensing Element
Semiconductor channel (nanowire) of the
transistor.
• The semiconductor channel is
fabricated using nanomaterials such
carbon nanotubes, metal oxide nanowires or Si nanowires.
• Very high surface to volume radio and very large portion of the
atoms are located on the surface. Extremely sensitive to
environment
20. NW grow across gap between electrodes
Growing NW connect to the second electrode
21. Form trench in Si and
Deposit catalyst
NW grows
perpendicular
NW connects to opposite
sidewall
22.
23.
24. Schematic shows two
nanowire devices, 1 and 2,
where the nanowires are
modified with different
antibody receptors.
Specific binding of a single
virus to the receptors on
nanowire 2 produces a
conductance change
(Right) characteristic of the
surface charge of the virus
only in nanowire 2. When
the virus unbinds from the
surface the conductance
returns to the baseline
value.
25.
26.
27.
28.
29.
30.
31.
32.
33. Self-Assembled Electrical Biodetector
Based on Reduced Graphene Oxide
Due to the presence of polar groups such as hydroxyl, carboxyl, and epoxy groups, GO is very
hydrophilic in comparison to graphene. For the purpose of device applications, the drawback
when using GO is that it is an insulating material. This can be overcome by the use of a
reduction procedure, which improves its conductivity, yielding reduced graphene oxide
(RGO).
Published in: Tetiana Kurkina; Subramanian Sundaram; Ravi Shankar Sundaram; Francesca Re; Massimo Masserini; Klaus Kern; Kannan Balasubramanian; ACS
Nano 2012, 6, 5514-5520.
34. (a) electrochemical functionalization of
Pt electrodes with tyramine (b) coating
of polytyramine on the electrode; (c)
coupling of GO to polytyramine; (d)
removal of polytyramine layer and
reduction of oxygen-containing groups
in argon at 350 °C . WE = working
electrode, CE = counter electrode, RE =
reference electrode.
35. Sensing of amyloid beta peptide using RGO immunosensor. (a) Schematic of RGO-FET
immunosensor; RE = reference electrode. (b) Field-effect characteristics of the RGO
immunosensor before and after functionalization and after the exposure of antibody-functionalized
device to 1 fM Aβ. (c) Control device showing the field-effect characteristics
of another RGO device without the antibody.
RGO was covered with Staphylococcus aureus protein A (SpA) through carbodiimide coupling.
SpA ensures a proper orientation of the subsequently immobilized antibodies since it has high
specificity to the Fc fragments. In a second step, SpA-RGO was modified with anti-Aβ-antibodies
by incubating the samples in a 50 mM antibody solution.
43. Quantitative assay:
resonance frequency mass-sensitive detector
f
43
A
A
f
k
eff
1
1 2
m
f
k
2
m m
1
2
f
eff
f1
m
f2
f1
f2
A mass sensitive resonator transforms an additional mass loading
into a resonance frequency shift mass sensor
B. Kim et al, Institut für Angewandte Physik - Universität Tübingen
44. 44
Magnetic sensing
• magnetic fields to sense magnetic nano-particles
that have been attached to biological
molecules.
45. Magnetic nano -
particle
Analyte
45
Stabilization of Magnetic Particles with various Streptavidin Conc.
10 min reaction
None 1 ng/ml 100 ng/ml 100 mg/ml
Anti-analyte Antibody
Cleaning
5 min deposition
T. Osaka, 2006
Ligand-functionalized
46. Activated pixel
46
Magnetic sensing
Magnetic head
Magnetic field sensor
Sensing plate
Idle pixel
Magnetic sensing
