A facile optosensing protocol based on molecularly imprinted polymer coated on CdTe quantum dots for highly sensitive and selective amoxicillin detection

- A molecularly imprinted polymer coated on CdTe quantum dots (MIP-QDs) was developed for the determination of amoxicillin.
- MIP-QDs showed a high sensitivity and selectivity for amoxicillin over other antibiotics.
- The developed method was applied to determine amoxicillin levels in food samples with a good recovery (85-102%).

A facile method for coating a molecularly imprinted polymer onto CdTe quantum dots (MIP-QDs) was successfully formulated and for the first time used as a highly selective and sensitive photoluminescence probe for the determination of trace amoxicillin. The MIP-QDs were prepared using a sol-gel process with 3-aminopropylethoxysilane as a functional monomer, tetraethoxysilane as a cross-linker and amoxicillin as a template molecule. After removal of the template molecule from the polymer layer, MIP-QDs containing cavities specific to amoxicillin were obtained. The hydrogen bonding between the amino group of 3-aminopropylethoxysilane and functional groups of amoxicillin and the specific size and shape of the cavity provided good selectivity. The photoluminescence intensity of MIP-QDs was more strongly quenched by amoxicillin compared to a non-imprinted polymer (NIP-QDs) with an imprinting factor of 43.6. Under optimum conditions, the photoluminescence intensity of MIP-QDs was decreased in response to increase amoxicillin concentration with good linearity in the range of 0.20-50.0 μg L−1. The limit of detection and the limit of quantitation were 0.14 μg L−1 and 0.46 μg L−1, respectively. The developed method showed good repeatability and reproducibility with the relative standard deviation being less than 6%. This developed method was successfully applied for the determination of amoxicillin in egg, milk and honey samples with a satisfactory recovery of 85-102% being achieved.

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