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Piezoelectric biosensors for organophosphate and carbamate pesticides: a review.

Marrazza G - Biosensors (Basel) (2014)

Bottom Line: Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection.Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity.This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy; E-Mail: giovanna.marrazza@unifi.it ; Tel.: +39-055-4573320;

ABSTRACT
Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection. Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity. This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis.

No MeSH data available.


Scheme of the relation between action on sensor surface and resulting frequency versus time curve, showing an antibody–antigen reaction as an example.
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biosensors-04-00301-f005: Scheme of the relation between action on sensor surface and resulting frequency versus time curve, showing an antibody–antigen reaction as an example.

Mentions: Because of their simplicity, piezoelectric quartz crystal sensors have been a great importance as competitive tools for bioanalytical assays and for the characterization of biomolecular interactions. In these biosensors, the bioreceptor is immobilized on quartz crystal, which resonate on application of an external alternating electric field. The biospecific reaction between the two interactive molecules, one immobilized on the surface and the other free in solution or gas phase, can be followed in real time. Samples are usually applied to the immobilized ligand on the sensor surface by a continuous constant flow. A constant analyte concentration at any part of the flow through cell is thus provided, and diffusion effects can be neglected. Moreover, an optimized cell design helps to avoid mass transport effects. Viscosity effects, however, can lead to frequency shifts interfering with the specific signal. Therefore, the biosensor should be calibrated with a viscous solution to determine the time in which the viscosity change generates a signal. This time interval should be excluded from the sensorgram. A sample sensorgram is given in Figure 5. After a measurement, the sensor has to be regenerated to remove bound analyte from the sensor surface. For this regeneration step, elution buffers as used in affinity chromatography can be applied as long as they do not destroy the native structure of the ligand. It should be noted that the QCM method does not allow the measurement of true affinities. Because the ligand is immobilized, one degree of freedom is lost. Therefore, the measured affinities could be influenced by decreased mobility and sterical hindrance. Furthermore, avidity effects resulting from multivalent binding might affect the apparent affinity. On the other hand, partial denaturation of the immobilized ligand may decrease the apparent binding affinity. Nevertheless, as real-time measurements are performed, the sensorgrams are capable of deducing not only the equilibrium binding constants but also the affinity rate constants.


Piezoelectric biosensors for organophosphate and carbamate pesticides: a review.

Marrazza G - Biosensors (Basel) (2014)

Scheme of the relation between action on sensor surface and resulting frequency versus time curve, showing an antibody–antigen reaction as an example.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4264360&req=5

biosensors-04-00301-f005: Scheme of the relation between action on sensor surface and resulting frequency versus time curve, showing an antibody–antigen reaction as an example.
Mentions: Because of their simplicity, piezoelectric quartz crystal sensors have been a great importance as competitive tools for bioanalytical assays and for the characterization of biomolecular interactions. In these biosensors, the bioreceptor is immobilized on quartz crystal, which resonate on application of an external alternating electric field. The biospecific reaction between the two interactive molecules, one immobilized on the surface and the other free in solution or gas phase, can be followed in real time. Samples are usually applied to the immobilized ligand on the sensor surface by a continuous constant flow. A constant analyte concentration at any part of the flow through cell is thus provided, and diffusion effects can be neglected. Moreover, an optimized cell design helps to avoid mass transport effects. Viscosity effects, however, can lead to frequency shifts interfering with the specific signal. Therefore, the biosensor should be calibrated with a viscous solution to determine the time in which the viscosity change generates a signal. This time interval should be excluded from the sensorgram. A sample sensorgram is given in Figure 5. After a measurement, the sensor has to be regenerated to remove bound analyte from the sensor surface. For this regeneration step, elution buffers as used in affinity chromatography can be applied as long as they do not destroy the native structure of the ligand. It should be noted that the QCM method does not allow the measurement of true affinities. Because the ligand is immobilized, one degree of freedom is lost. Therefore, the measured affinities could be influenced by decreased mobility and sterical hindrance. Furthermore, avidity effects resulting from multivalent binding might affect the apparent affinity. On the other hand, partial denaturation of the immobilized ligand may decrease the apparent binding affinity. Nevertheless, as real-time measurements are performed, the sensorgrams are capable of deducing not only the equilibrium binding constants but also the affinity rate constants.

Bottom Line: Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection.Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity.This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy; E-Mail: giovanna.marrazza@unifi.it ; Tel.: +39-055-4573320;

ABSTRACT
Due to the great amount of pesticides currently being used, there is an increased interest for developing biosensors for their detection. Among all the physical transducers, piezoelectric systems have emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity. This paper presents an overview of biosensors based on the quartz crystal microbalance, which have been reported in the literature for organophosphate and carbamate pesticide analysis.

No MeSH data available.