Biosensors are nowadays ubiquitous in biomedical diagnosis as well as a wide range of other areas such as point-of-care monitoring of treatment and disease progression, environmental monitoring, food control, drug discovery, forensics and biomedical research. A wide range of techniques can be used for the development of biosensors. Their coupling with high-affinity biomolecules allows the sensitive and selective detection of a range of analytes. We give a general introduction to biosensors and biosensing technologies, including a brief historical overview, introducing key developments in the field and illustrating the breadth of biomolecular sensing strategies and the expansion of nanotechnological approaches that are now available

1. Running head: BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 0
Department of environmental sciences
Biosensors
Mahnoor Yousaf
Syeda Ayesha Zaidi
Taskeen Rubab
Zainab Jawed
Zarmeen Faiz
Lahore college for women university
DEPARTMENT OF
ENVIRONMENTAL
SCIENCESBIOSENSORS
Biosensors and its utilization in environment
Abstract:
Biosensors and
its utilization in
environment
Submitted by:
Taskeen
rubab2025117079

2. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 1
Abstract
Biosensors are nowadays ubiquitous in biomedical diagnosis as well as a wide range of other
areas such as point-of-care monitoring of treatment and disease progression, environmental
monitoring, food control, drug discovery, forensics and biomedical research. A wide range
oftechniques can be used for the development of biosensors. Their coupling with high-affinity
biomolecules allows the sensitive and selective detection of a range of analytes. We give a
general introduction to biosensors and biosensing technologies, including a brief historical
overview, introducing key developments in the field and illustrating the breadth of biomolecular
sensing strategies and the expansion of nanotechnological approaches that are now available
Keywords: [affinity reagents, biosensors, glucose sensor, nanomaterials, pregnancy test]
Table of content
 Introduction 3
 Background 4
 Methodology 6
 Benefits 9
 Applications 11
 Conclusion 12
 Reference 13

3. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 2
Department of environmental sciences
Biosensors
A biosensoris a device that measures biological or chemical reactions by generating signals proportional to the
concentration of an analyte in the reaction. Biosensors are employed in applications such as disease monitoring, drug
discovery, and detection of pollutants, disease-causing micro-organisms and markers that are indicators of a disease in
bodily fluids (blood, urine, saliva, sweat).
A typical biosensor is represented as it consists of the following components.
 Analyte: A substance of interest that needs detection. For instance, glucose is an
‘analyte’ in a biosensor designed to detect glucose.
 Bioreceptor: A molecule that specifically recognizes the analyte is known as a
bioreceptor. Enzymes, cells, aptamers, deoxyribonucleic acid (DNA) and
antibodies are some examples of bioreceptors. The process of signal generation
(in the form of light, heat, pH, charge or mass change, etc.) upon interaction of the
bioreceptor with the analyte is termed bio-recognition.
 Transducer: The transducer is an element that converts one form of energy into
another. In a biosensor the role of the transducer is to convert the bio-recognition
event into a measurable signal. This process of energy conversion is known as
signalization. Most transducers produce either optical or electrical signals that are
usually proportional to the amount of analyte–bioreceptor interactions.
 Electronics: This is the part of a biosensor that processes the transduced signal
and prepares it for display. It consists of complex electronic circuitry that
performs signal conditioning such as amplification and conversion of signals from
analogue into the digital form. The processed signals are then quantified by the
display unit of the biosensor.

4. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 3
 Display: The display consists of a user interpretation system such as the liquid
crystal display of a computer or a direct printer that generates numbers or curves
understandable by the user. This part often consists of a combination of hardware
and software that generates results of the biosensor in a user-friendly manner. The
output signal on the display can be numeric, graphic, tabular or an image,
depending on the requirements of the end user.
Background
The history of biosensors dates back to as early as 1906 when M. Cremer demonstrated
that the concentration of an acid in a liquid is proportional to the electric potential that arises
between parts of the fluid located on opposite sides of a glass membrane. However, it was only
in 1909 that the concept of pH (hydrogen ion concentration) was introduced by Soren Peder
Lauritz Sorensen and an electrode for pH measurements was realized in the year 1922 by W.S.
Hughes. Between 1909 and 1922, Griffin and Nelson first demonstrated immobilization of the
enzyme invertase on aluminum hydroxide and charcoal. The first ‘true’ biosensor was developed
by Leland C. Clark, Jr in 1956 for oxygen detection. He is known as the ‘father of biosensors’
and his invention of the oxygen electrode bears his name: ‘Clark electrode’. The demonstration
of an amperometry enzyme electrode for the detection of glucose by Leland Clark in 1962 was
followed by the discovery of the first potentiometric biosensor to detect urea in 1969 by
Guilbault and Montalvo, Jr. Eventually in 1975 the first commercial biosensor was developed by
Yellow Spring Instruments (YSI). Table 1 shows the historical overview of biosensors in the
period 1970–1992. Ever since the development of the i-STAT sensor, remarkable progress has
been achieved in the field of biosensors. The field is now a multidisciplinary area of research that

5. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 4
bridges the principles of basic sciences (physics, chemistry and biology) with fundamentals of
micro/nano-technology, electronics and applicatory medicine. The database ‘Web of Science’ has
indexed over 84000 reports on the topic of ‘biosensors’ from 2005 to 2015.
Table 1.
Important cornerstones in the development of biosensors during the period 1970–1992
 1970 Discovery of ion-sensitive field-effect transistor (ISFET) by Bergveld
 1975 Fiber-optic biosensor for carbon dioxide and oxygen detection by Lubbers
and Opitz
 1975 First commercial biosensor for glucose detection by YSI
 1975 First microbe-based immunosensor by Suzuki et al. [10]
 1982 Fiber-optic biosensor for glucose detection by Schultz
 1983 Surface plasmon resonance (SPR) immunosensor by Liedberg et al.
 1984 First mediated amperometry biosensor: ferrocene used with glucose
oxidase for glucose detection
 1990 SPR-based biosensor by Pharmacia Biacore
 1992 Handheld blood biosensor by I-STAT

6. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 5
Methodology
Types of electrochemical sensors: -
1- Potentiometric sensors:
They measure the change in charge density at the surface of an electrode.
2-Amperometric sensors:
Amperometric sensors monitor currents generated when an exchange of electrons take place
either directly or indirectly between an electrode and a biological system.
3-Conductimetric:
In such sensors, the measurement of solution resistance provides the concentration of charge.
These sensors are therefore not species-selective. Conductimetric sensors are called because they
measure electrical conductance as their signal change.
Components of Biosensors:
A biosensor is a device used for the detection of a physiological change. It consists of three
components;
1- Biological recognition elements, which help differentiate the target analyte from various other
molecules.
2- A Transducer, which helps convert the reaction of the glucose molecules into a current.

7. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 6
3- The electronic circuitry needed to convert the signal into a user-readable form.
Biological Components:
 Analyte:
Analyte means any substance or object we use for analysis. It can be;
 Molecule
 Protein
 Toxin
 Peptide
 Vitamin
 Sugar
 Metal ion
 Urine

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 Bioelement:
 It has function to detect biological responses;
 Enzyme
 Antibody
 Nucleic acid
 Tissue
 Microbial
 Polysaccharide
There are many biosensors to measure different physiological changes. Here we discuss the
Glucose sensing implantable sensors.
Glucometer:
 The device used to monitor glucose levels in blood of diabetic patients is called as
glucometer.
 To do glucose testing, a diabetic uses a glucose testing meter, which uses a glucose
testing strip.

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 Most glucose meters are based on electrochemical technology, they use electrochemical
test strips to perform the measurement.
 A small drop of the solution to be tested is placed on a disposable test strip that the
glucose meter uses for the glucose measurement.
Working Principle:
 In each test strip, there is an enzyme called glucose oxidase. This enzyme reacts with the
glucose in the blood sample and creates an acid called gluconic acid.
 The gluconic acid then reacts with another chemical in the testing strip called
ferricyanide. The ferricyanide and gluconic acid then combine to create ferrocyanide.
 Once ferrocyanide has been created, the device runs an electronic current through the
blood sample on the strip.
 This current is then able to read the ferrocyanide and determine how much glucose is in
the sample of blood on the testing strip. That number is then displayed on the screen of
the glucose testing meter.
Methods
Methods used in electrochemical measurement of glucose:
The two most common methods used in electrochemical measurement of glucose are;
1. Colorimetric method
2. Amperometric method

10. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 9
 Colorimetric Method:
 In this method, the typical sensors such as LEDs or photo sensors form the analog
interface. These sensors are followed by a Transimpedance Amplifier for the glucose
concentration measurement in the solution.
 The Color Reflectance principle is used in this method to sense the color intensity in the
reaction layer of the test strip by the photometry.
 The glucose meter generates a numerical value, that is a measurement of the glucose
concentration present in the solution.
 Amperometric Method:
 In this method, the electrochemical test strip contains a capillary that is used to draw in
the solution placed at one end of the test strip.
 The test strip also contains an enzyme electrode containing a reagent such as Glucose
Oxidase.
 Glucose undergoes a chemical reaction in the presence of enzymes and electrons are
produced during the chemical reaction.
 These electrons are measured and this is proportional to the concentration of glucose in
the solution.
 An ambient temperature measurement is also made in order to compensate for the effect
of temperature on the rate of the reaction.
 The solution sample (blood) is placed on the test strip and the reaction of the glucose with
the enzyme takes place.
 The flow of electrons will correspond to the flow current through the working and the
reference electrodes.

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 This current will change according to the glucose concentration.
 This current is measured using a transimpedance amplifier (current to voltage converter)
and an analog-to-digital converter (ADC).
 The output of the transimpedance amplifier will be seen as a variation in the voltage with
varying glucose concentrations in the solution.
Benefits
 Rapid and continuous measurement
 Rapid and continuous measurement.
 High specificity.
 Very less usage of reagents required for calibration.
 Fast response time.
 Ability to measure non-polar molecules that cannot be estimated by other
conventional devices
 High specificity
 Food Analysis
 Study of biomolecules and their interaction
 Crime detection
 Medical diagnosis (both clinical and laboratory use)
 Industrial Process Control
 Detection systems for biological warfare agents Manufacturing of
pharmaceuticals and replacement organs

12. BIOSENSORS AND ITS UTILIZATION IN ENVIRONMENT 11
Applications
 Common healthcare checking Metabolites
 Measurement Screening for sickness Insulin treatment
 Clinical psychotherapy & diagnosis of disease
 In Military and Veterinary Drug improvement offense detection
 Processing & monitoring in Industrial Ecological pollution control Diagnostic &
Clinical Agricultural
 Applications & Environmental Industrial Applications Study & Interaction of
Biomolecules Development of Drug
 Detection of Crime
 Medical Diagnosis Monitoring of Environmental Field Quality
 Control Process Control in Industries Pharmaceuticals Organs
 Replacement Manufacturer
Conclusion
Biosensor technology is in its infancy but there is unlimited potential to reduce costs and
still provide a respectable quality of care. Intel and other companies are taking steps in the right
direction to provide products and services that will benefit patients and help retain their dignity.
“According to the U.S. Healthcare Financing Administration, home care is the largest growing
segment of health care. Experts believe that care for the elderly will increasingly be provided in
homes and in low-skill care facilities as opposed to institutions.” (Intelligent Biosensors to
Monitor Seniors Movements, 2007) These statements solidify the viability of biosensors and
other telehealth "

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References
https://www.clinfowiki.org/wiki/index.php/Biosensor
https://www.onlinebiologynotes.com
https://www.clinfowiki.org/wiki/index.php/Biosensor#:~:text=single-
https://www.azosensors.com/amp/article.aspx?ArticleID=402