Microscale chemical and enzyme sensor arrays prepared by microcontact printing

Fluorescence-based integrated chemical and enzyme sensor arrays on which two kinds of 10 μm inside diameter (i.d.) sensor spots were arranged alternately on one chip were developed using microcontact printing. Fluorescein isothiocyanate (FITC), a ruthenium complex, and europium tetracycline (EuTc) were stamped onto diamondlike carbon (DLC) sputtered glass slides for pH, oxygen, and hydrogen peroxide sensors, respectively. After printing oxygen sensor spots, pH sensor spots were stamped between the oxygen sensor spots using the same polydimethylsiloxane (PDMS) stamp. In the same way, glucose oxidase and lactate oxidase spots were stamped in an alternating pattern onto H²O² sensor spots. Each sensor in the integrated sensor showed specific responses independently.