Summary

The control of chemical residues is essential in honey’s marketing to ensure consumer safety. Equipments available in the market reach the required limit of detection (LOD) (e.g. Liquid Cromatography- HPLC) but are not suitable for in-situ implantation in honey packaging industry. The reasons are:

• High qualified staff required
• High cost
• Time-consuming

Other approaches available in the market, although faster and without the need of qualified staff, do not reach the required LODs. Piezoelectric immunosensors based on High Fundamental Frequency Quartz Crystal Microbalance (HFF-QCM) combined with an antigen-antibody recognition process, are alternative or complementary technologies suitable for chemical residues control in food.

The analytical performance of AWS-A20 and AWS-F20 platforms (based on HFF-QCM technology) has been tested for the detection of pesticide residues (DDT) in honey.

AWS platforms lead to the following benefits:

• Lower cost
• Less sample/reagent consumption
• Label-free, direct and real time transduction

DDT standard curves performed in laboratory buffer provided:

• Sensitivity (estimated as the I₅₀ value): 0.62 µg/L
• LOD in the 0.05 – 0.1 µg/L range

Remarks

• A HFF-QCM immunosensors for DDT insecticide has been developed
• Efficient biosensing interfaces were achieved by covalent functionalization of the sensor gold electrodes with mixed alkane-thiol self-assembled monolayers (mSAMs)
• High-sensitivity monoclonal antibodies were used as the bio-recognition element of the target analyte in a competitive immunoassay format.
• The limits of detection (LOD) and quantification (LOQ) and the working range (WR) of the developed HFF-QCM immunosensor for DDT are in the same order of magnitude as those previously reported for ELISA and SPR immunosensor.

 

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