Preparation of new molecularly imprinted quartz crystal microbalance hybride sensor system for 8-hydroxy-2'-deoxyguanosine determination.

The routine measurement of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in biological samples is a difficult analytical problem due to the low levels of the analyte and complex matrix. A new 8-OHdG imprinted quartz crystal microbalance (QCM) sensor has been developed for selective determination of 8-OHdG in serum samples. To fulfil the desired results, we have used methacryloyl aminoantipyrine-Fe(III) [MAAP-Fe(III)] and methacryloyl histidine-Pt(II) [MAH-Pt(II)] as metal-chelating monomers via double metal coordination-chelation interactions for the preparation of additional selective molecular imprinted polymers (MIP). The study includes the measurement of binding interaction of 8-OHdG imprinted quartz crystal microbalance (QCM) sensor, selectivity experiments and analytical performance of QCM chip. The obtained results have showed that the application of double metal-chelate monomer systems has been more effective than single metal-chelate monomer systems. In this study, the detection limit and the linear working range were found to be 0.0075 and 0.0100-3.5 microM, respectively. The affinity constant (K(affinity)) was found to be 1.54x10(5) M(-1) for 8-OHdG using MAH-Pt-8-OHdG-MAAP-Fe based thin film. Also, selectivity of prepared QCM sensor was found as being very high in the presence of competitive species. At the last step of this procedure, 8-OHdG level in blood serum which belongs to a intestinal cancer patient was determined by the prepared QCM sensor.