Bio sensors – find manufacturers and suppliers

Biosensors detect biological or chemical substances using a biological recognition element and convert the reaction into a measurable signal.

They are used to detect substances such as glucose, lactate, enzymes, antibodies, microorganisms, toxins and other biological or chemical analytes.
A biosensor typically consists of a biological recognition element, a transducer and evaluation electronics. The recognition element reacts selectively with the target substance. The transducer converts this reaction into an electrical, optical, thermal or mechanical signal.
Biosensors are used in medical diagnostics, biotechnology, food analysis, environmental monitoring and industrial analysis and process systems.
Depending on the application, they are available as individual sensing elements, measuring cells, probes, test strips, flow-through sensors or components of complete analytical instruments.
The following provides an overview of typical types, applications, advantages, limitations and important selection criteria for biosensors.

Types of biosensors

Enzymatic biosensors

Enzymatic biosensors use enzymes as biological recognition elements.
The enzyme reacts selectively with the substance to be measured. This produces measurable reaction products or changes that are detected by the transducer.
Enzymatic biosensors are used, for example, to measure glucose, lactate, glutamate, glutamine, cholesterol or alcohol.
Measurement accuracy depends, among other factors, on enzyme activity, temperature, pH value and sample composition.

Immunosensors

Immunosensors are based on the specific binding between antibodies and antigens.
They can detect proteins, pathogens, allergens, toxins and other biological target substances.
The binding reaction is evaluated electrochemically, optically or through a change in mass on the sensor surface.
For reliable results, cross-reactions with similar substances must be minimised as far as possible.

Nucleic acid-based biosensors

Nucleic acid-based biosensors detect specific DNA or RNA sequences.
For this purpose, matching nucleic acid sections are immobilised on a sensor surface. When the target sequence binds to this surface, an evaluable signal is generated.
Such sensors can be used to detect genetic characteristics, biological contamination or certain microorganisms.

Cell-based biosensors

Cell-based biosensors use living cells or cell components as recognition elements.
The cells react to specific substances, environmental conditions or toxic influences. Changes in metabolism, growth or other cellular functions are then measured.
Cell-based systems are used in pharmaceutical testing, toxicology and environmental analysis.

Electrochemical biosensors

Electrochemical biosensors convert a biological or chemical reaction into an electrical signal.
Depending on the design, electrical currents, voltages, resistances or impedances are measured.
Electrochemical biosensors can be designed in compact formats and are often suitable for small sample volumes as well as mobile or automated measuring systems.
However, the electrode surface can be affected by deposits, contamination or components of the sample.

Optical biosensors

Optical biosensors detect changes in light signals.
Measured parameters include absorption, fluorescence, luminescence, reflection and changes in refractive index.
Optical biosensors can achieve high sensitivity and, depending on the design, may detect several substances simultaneously.
Turbid, coloured or highly light-scattering samples can impair measurement.

Piezoelectric biosensors

Piezoelectric biosensors detect changes in mass on an oscillating sensor surface.
When the target substance binds to the coated surface, the resonance frequency of the sensing element changes.
Such systems are suitable for investigating binding processes. Temperature, viscosity and non-specific deposits can influence the measurement result.

Applications of biosensors

Medical diagnostics

In medical diagnostics, biosensors are used to determine metabolic values, biomarkers, pathogens and other medically relevant parameters.
Among the best-known applications are glucose and lactate measurement.
Depending on the design, biosensors can form part of laboratory instruments, portable measuring devices, test strips or continuously operating measuring systems.

Biotechnology and fermentation

In biotechnological processes, biosensors monitor nutrients, metabolic products and process conditions.
Measured values such as glucose, lactate, glutamate, glutamine or oxygen provide information about the progress of fermentation processes and cell cultures.
Rapid detection makes it possible to identify deviations at an early stage and adjust process conditions.

Pharmaceutical research

In pharmaceutical research, biosensors are used to investigate active substances, proteins, binding reactions and cellular responses.
They can automate measurement series and detect changes in biological processes within a short time.
Reproducible sample conditions, suitable calibration and a controlled sensor surface are required for comparable results.

Food and beverage industry

Biosensors can detect ingredients, allergens, microorganisms, toxins and residues in food and beverages.
They are used to inspect raw materials, production processes and finished products.
Fats, proteins, colourants, particles and other sample components can influence the measurement result. The sensor must therefore be suitable for the respective food matrix.

Environmental analysis

In environmental analysis, biosensors are used to detect pollutants, microorganisms, pesticides and organic contamination.
Water, wastewater, soil extracts and other environmental samples can be analysed.
Robust sensor housings, simple operation and low sensitivity to temperature fluctuations are advantageous for mobile applications.

Industrial process monitoring

Biosensors can be integrated into industrial analysis and process systems.
They monitor biological or chemical parameters in reactors, pipelines, measuring cells and automated sampling systems.
Resistance to process media, adequate service life and the possibility of cleaning or replacing the sensing element are important for continuous operation.

Advantages of biosensors

• Selective detection of specific biological or chemical substances
• Short measuring times
• Low sample requirements
• Compact designs
• Integration into mobile and automated measuring systems
• Continuous or repeated measurements possible
• Different biological recognition elements available
• Various electrical and optical output signals
• Use in laboratories, production environments and mobile analysis
• Possibility of direct process monitoring

Limitations of biosensors

• Biological recognition elements can be sensitive to temperature, moisture, pH value and chemicals.
• Enzymes, antibodies, cells and other biological components often have a limited storage and operating life.
• Sample components can accumulate on the sensor surface and alter the measurement result.
• Similar substances can cause cross-reactions, depending on the recognition element.
• Calibration can change during operation and must be checked regularly.
• Some biosensors are designed for single use only.
• Cleaning and regeneration of reusable sensors can be time-consuming.
• Laboratory results cannot always be transferred directly to real samples or industrial processes.
• The performance of a biosensor often depends strongly on the composition of the sample.
• Standardised comparison values from different manufacturers are not available for every application.

Important selection criteria for biosensors

Target substance

The first step is to define which substance or group of substances is to be detected.
The biosensor must contain a suitable biological recognition element for the respective analyte.
Possible accompanying substances and chemically similar compounds must also be considered, as they can influence the measurement result.

Measuring range and detection limit

The measuring range must cover the expected concentrations completely.
A sufficiently low detection limit is required for very low concentrations.
However, a particularly sensitive sensor is not automatically better if the relevant concentration range is significantly higher.

Selectivity

Selectivity describes how specifically the biosensor responds to the target substance.
In complex samples, similar molecules or other components can generate unwanted signals.
The manufacturer should therefore specify known cross-sensitivities and the sample types for which the sensor has been tested.

Response time

The required response time depends on the application.
For continuous process monitoring or rapidly changing measurements, the sensor must detect changes within a short period.
For individual laboratory analyses, a longer measuring time may be acceptable if it improves sensitivity or accuracy.

Sample type and sample preparation

Blood, cell culture media, food, wastewater and industrial process liquids place different demands on a biosensor.
Viscosity, particle content, colour, temperature and chemical composition can influence measurement.
It must be determined whether the sample needs to be diluted, filtered, prepared or temperature-controlled.

Service life and storage stability

Biological recognition elements can lose activity during storage and operation.
Shelf life, permitted storage temperature, packaging, moisture protection and possible refrigeration requirements must be considered.
For reusable sensors, the number of possible measuring or regeneration cycles is also relevant.

Single-use or reusable sensor

Single-use sensors reduce cleaning requirements and the risk of carryover between samples.
Reusable sensors can be more economical for frequent measurements but require suitable cleaning, calibration and regeneration procedures.
The selection depends on measuring frequency, hygiene requirements and cost per measurement.

Output signal and interfaces

The output signal must be compatible with the existing measuring or control system.
Depending on the biosensor, current, voltage, frequency, digital or optical signals are provided.
Suitable interfaces, stable data transmission and integration into evaluation software are important for automated applications.

Calibration

Biosensors require suitable calibration for the intended measuring range and sample type.
Calibration intervals, reference solutions, temperature compensation and possible drift must be considered.
Calibration should be documented and traceable to ensure comparable results.

Environmental and process conditions

Temperature, pressure, moisture, vibration, electromagnetic interference and aggressive media can influence operation.
For industrial applications, housings, seals, sensor surfaces and electrical connections must be designed for the respective conditions.

Cleaning and replacement

For reusable biosensors, it must be determined how the sensor surface can be cleaned or regenerated.
Cleaning agents and disinfection procedures must not damage the biological recognition element.
A replaceable sensing element can simplify maintenance and servicing.

Summary

Biosensors combine biological recognition elements with electrical, optical, thermal or mechanical transducers.
Depending on the application, enzymatic, immunological, nucleic acid-based, cell-based, electrochemical, optical or piezoelectric biosensors are used.
Typical applications include medical diagnostics, biotechnology, pharmaceutical research, food analysis, environmental monitoring and industrial process control.
The main selection criteria include the target substance, measuring range, selectivity, detection limit, response time, sample type, service life and interface.
As biological recognition elements can be sensitive to environmental conditions and ageing, storage, calibration, cleaning and replacement must be considered during procurement.

Biosensors are available from various manufacturers and suppliers. Comprehensive information about manufacturers and suppliers of biosensors from around the world can be found on Exportpages.