Optimization of the surface initiated polymerization of molecular imprinted methacrylate polymer on gold electrode for the detection of testosterone

Abstract EN

In this work a sensor based on moleculary imprinted polymer (MIP) was fabricated to detect testosterone which is an endocrine disruptor.

The methacrylic MIP is polymerized on the gold electrode surface, through the grafting of the initiator 2,2’-Azobis(2-Amidinopropane) (APA) on gold surface.

A mixed SAM was firstly built from 1-hexanethiol and an alkanethiol bearing carboxyl end groups whose chain length determines the distance of (APA) initiator from the surface of the gold electrode.

Ferrocene-carboxylic acid was used to quantify free amine group of the (APA) initiator fixed on mixed SAM without bridging and ferrocenyl methyl methacrylate was used to check through cyclic voltammetry (CV) that methacrylate monomers polymerize on the electrode surface.

Using these tools, the SAM composition was optimized as 1-hexanethiol (HT): 11-mercaptoundecanoic acid (AMU) with a molar ration of 50/50.

The detection of testosterone with the MIP-sensor was done using electrochemical impedance spectroscopy.

A linear range of 1pg/L to 1 ng/L was obtained, with a detection limit of 1 pg/L.