Fabrication of an atrazine acoustic immunosensor based on a drop-deposition procedure

Abstract

Among the various novel analytical systems, immunosensors based on acoustic waves are of emerging interest because of their good sensitivity, real-time monitoring capability, and experimental simplicity. In this work, piezoelectric immunosensors were constructed for the detection of atrazine through the immobilization of specific monoclonal anti-atrazine antibodies on thiolated modified quartz crystal microbalances (QCMs). The immunoassay was conducted by a novel drop-deposition procedure using different atrazine dilutions in phosphate buffer solution ranging from 10(-10) to 10(-1) mg/mL. The immunoreactions between varying contents of atrazine and its antibody were dynamically exhibited through in situ monitoring of the frequency and motional resistance changes over 20 min. Thus, atrazine recognition by the anti-atrazine antibody leads to a decrease of the resonant frequency that is proportional to a given atrazine concentration. Interestingly, the motional resistance also increased proportionally during the measurements, which could be attributed to the specific viscoelastic properties and/or conformation changes of the antibodies once the immunoreactions occurred. By combining the measurements of frequency with those of motional resistance, additional information was provided about the interaction between the atrazine-named antigen and its respective antibody. Finally, the analytical specificity of the immunosensor to atrazine was evaluated through the response to a nonspecific anti-human IgG antibody-modified QCM crystal under the same drop conditions.

Advanced biosensors for detection of pathogens related to livestock and poultry

“…Specificity of the system relies on oligonucleotide probes covalently immobilized on the sensing surface. Techniques, such as optical [ 120 ], acoustic [ 121 ], electrochemical [ 122 ], microwire [ 123 ] and localized surface plasmon resonance [ 124 ], have been proposed for traducing the hybridization with the specific target nucleic acid to the pathogen detection. For instance, an organic light emitting diode (OLED) biosensor can be employed for the detection of Campylobacter in poultry meat samples, using a DNA probe attached to a glass slide (Figure 9 ).…”

Innovative Sensor Approach to Follow Campylobacter jejuni Development

“…They are essentially DNA-biosensors, of which specificity is due to oligonucleotide probes covalently immobilized on the sensing surface. Several optical [12], acoustic [13] and electrochemical [14] techniques have been proposed for traducing the hybridization with the specific target nucleic acid to the pathogen detection [15]. As an example, quartz crystal microbalance (QCM) immunosensors, using monoclonal and polyclonal antibody systems coupled with the use of gold nanoparticles (AuNPs) to increase the sensitivity, were used [16].…”