Towards the development of molecularly imprinted polymer based screen-printed sensors for metabolites of PAHs

This paper describes the fabrication of a sensor for 1-hydroxypyrene (1-OHP ) based on a screen-printed carbon electrode (SPCE) modified with a molecul arly imprinted polymer (MIP); 1-OHP was chosen as a model metabolite of pol yaromatic hydrocarbons (PAHs). It was shown that 1-OHP could be readily oxi dised at a plain SPCE and the electrochemical mechanism was found to involv e an ECE (electron transfer-chemical reaction-electron transfer) process. T he MIP for 1-OHP was prepared using only divinylbenzene (DVB) and styrene a s monomers and the binding was only based on hydrophobic interactions. Batc h binding studies revealed that optimum uptake of 1-OHP by the MIP occurred from solutions containing 35% water in methanol. Selectivity of the bindin g sites in the MIP was examined by performing uptake studies in the same so lution containing either phenol or 1-naphthol; the specific binding of 1-OH P was twenty times greater than the former and five times greater than the latter. Preliminary calibration studies were performed with the MIP-SPCE us ing a two-step approach; accumulation was carried out in 35% water in metha nol followed by measurement in 50% methanol-0.025 mol dm(-3) phosphate buff er pH 12. This two-step non-competitive affinity assay gave encouraging res ults and indicated potential for use in pollution studies.