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Chemical functionalization of thin film surfaces for MR biochip development
Recently, along with the emergent technology of magnetoresistive sensors-based devices, micron- and nano-sized superparamagnetic beads found out a novel application as reporter systems in the detection and quantification of biomolecular recognition events. The interaction between these bio-derivatized magnetic particles and different biochemically treated surfaces are meant to be mainly specific, however several other non-specific interactions tend to be present. Initially SiO2 thin films were used presenting several drawbacks, such as non-specific adsorption and lack of reproducibility. Recently, gold thin-films were tested with a compatible chemistry and despite the lower functional density it successfully overcame the former non-specificity in SiO2, helping to avoid false responses.
Fig.7-Different blocking solution (BSA 1%, Salmon DNA and thiol- and amino- functional PEG polymers) were tested in order to minimize the magnetic particles non-specific adsorption to functional thin-films SiO2 and gold.