Dual recognition elements for selective determination of progesterone based on molecularly imprinted electrochemical aptasensor

A novel molecularly imprinted electrochemical aptasensor (MIEAS) was constructed for selective progesterone (P4) detection based on SnO2-graphene (SnO2-Gr) nanomaterial and gold nanoparticles (AuNPs). SnO2-Gr with a large specific area and excellent conductivity improved the adsorption capacity of P4. Aptamer, as biocompatible monomer, was captured by AuNPs on modified electrode through Au-S bond. An electropolymerized molecularly imprinted polymer (MIP) film consisted of p-aminothiophenol as chemical functional monomer and P4 as template molecule. Due to the synergetic effect of MIP and aptamer towards P4, this MIEAS exhibited better selectivity than the sensor with MIP or aptamer as single recognition element. The prepared sensor had a low detection limit of 1.73 x 10-15 M in a wide linear range from 10-14 M to 10-5 M. Satisfactory recovery obtained in tap water and milk samples proved that this sensor had great potential in environmental and food analysis.

Automated summary

A novel molecularly imprinted electrochemical aptasensor (MIEAS) using SnO2-Gr nanomaterial and AuNPs was developed for selective progesterone (P4) detection. The MIEAS exhibited improved selectivity due to the synergetic effect of the molecularly imprinted polymer (MIP) and aptamer towards P4. The sensor had a low detection limit of 1.73 x 10-15 M and showed satisfactory recovery in tap water and milk samples, indicating its potential in environmental and food analysis.