Fabrication of QCM sensor array and PDMS micro chamber for biosensor applications

In this work, an array of quartz crystal microbalance (QCM) sensors is fabricated on a single quartz crystal substrate and attached with poly(dimethylsiloxane) (PDMS) micro chamber for using in flow-injection system. The Cr/Au electrode array is deposited on both side of quartz substrate by sputtering through electroplated microshadow mask. PDMS micro chamber was fabricated by mold casting technique with SU-8 mold. Fabricated PDMS micro chamber and QCM sensor array were attached together for using in flow-injection system. In our experiment, the QCM electrodes were coated with the carboxylic poly(vinyl chloride) (PVC-COOH) and then the carboxylic group was activated with carbodiimide hydrochloride (EDC) and N-hydroxylsuccinimide (NHS) for protein binding. The scanning electron micrograph shown the trapped protein on the modified sensing layer, it confirmed that our QCM sensor and PDMS micro chamber can be used as QCM biosensor array. This new QCM sensor array provide possibility of multiple detection in small amount of sample within a single quartz crystal substrate that avoid the error signal from the different properties of each sensor in an array.