A molecularly imprinted electrochemical sensing platform based on the signal amplification system fabricated with the theoretically optimized monomer for specific determination of formaldehyde

Molecular imprinting technique (MIT) has proved to be a promising and potential strategy in sensing fields on account of remarkable specific recognition function. Noble metal nanoparticles, which could catalyze diverse substances such as formaldehyde, methanol, etc., have been applied as sensing probes in electrochemical sensing. However, few sensors have been reported yet based on the combination of MIT and metal nanoparticles to simultaneously achieve the specific and ultrasensitive sensing. Herein, specific determination for formaldehyde is realized on the basis of a molecular imprinted bi-nanospherical signal amplification system constructed by gold nanoclusters (Au NCs) and polydopamine nanospheres (PDA NPs). In detail, Au NCs are obtained and uniformly immobilized on PDA NPs surface, yielding the bi-nanospheres with a huge surface area. Additionally, density functional theory is applied to optimize functional monomers, and then acrylamide is chosen to synthesize the molecularly imprinted polymers with the optimal recognition ability towards formaldehyde molecules. Impressively, the pre-fabricated sensor exhibits a wide detection range of 0.2 mu M - 0.02 M and a low detection limit of 0.1 mu M (S/N >= 3) for formaldehyde detection. More importantly, the introduction of MIPs endows the sensor with satisfactory selectivity and avoids the interference of other analogs.