Love Wave Immunosensor for the Detection of Carbaryl Pesticide

Abstract

A Love Wave (LW) immunosensor was developed for the detection of carbaryl pesticide. The experimental setup consisted on: a compact electronic characterization circuit based on phase and amplitude detection at constant frequency; an automated flow injection system; a thermal control unit; a custom-made flow-through cell; and Quartz/SiO2 LW sensors with a 40 μm wavelength and 120 MHz center frequency. The carbaryl detection was based on a competitive immunoassay format using LIB-CNH45 monoclonal antibody (MAb). Bovine Serum Albumin-CNH (BSA-CNH) carbaryl hapten-conjugate was covalently immobilized, via mercaptohexadecanoic acid self-assembled monolayer (SAM), onto the gold sensing area of the LW sensors. This immobilization allowed the reusability of the sensor for at least 70 assays without significant signal losses. The LW immunosensor showed a limit of detection (LOD) of 0.09 μg/L, a sensitivity of 0.31 μg/L and a linear working range of 0.14–1.63 μg/L. In comparison to other carbaryl immunosensors, the LW immunosensor achieved a high sensitivity and a low LOD. These features turn the LW immunosensor into a promising tool for applications that demand a high resolution, such as for the detection of pesticides in drinking water at European regulatory levels.

Analytical Methods for Pesticide Residues in the Water Environment

“…In the presence of the analyte, the aptamer undergoes a structural rearrangement and is no longer able to bind to the surface of the nanoparticle, thereby releasing the gold nanoparticle to resume its peroxidase-like activity and oxidize a colorless substrate into its purple product. Rocha-Gaso et al (2014) detected carbaryl using a love wave immunosensor. This piezoelectric sensor was prepared by immobilizing a bovine serum albumin-CNH carbaryl hapten-conjugate onto the surface of an acoustic transducer.…”

Surface Acoustic Wave Immunosensor for Detection of Botulinum Neurotoxin

“…The measurement system with a vector analyzer, apart from the phase (SAW phase at a fixed frequency), allowed for the recording of the amplitude and frequency of the resonance peak. However, since the best signal-to-noise ratio characterized the phase signal, further analysis was based on this signal (similarly as in the work [ 23 ]). The analytical signal was adopted as the phase shift between the beginning of toxin dosing and the following steady-state value of phase (or, in a transient state—value of phase after 10 min from the start of toxin dosing).…”

Quartz Crystal Microbalance Electronic Interfacing Systems: A Review

“…Higher sensitivity was reported through the 100 MHz crystal, compared to 50 MHz and conventional 10 MHz crystals, with limits of detection, respectively. Similar experimental setup was also successfully used to characterize Love-wave immunosensors in [ 122 ], indicating its adaptability and robustness for various applications.…”