Novel disposable biochip platform employing supercritical angle fluorescence for enhanced fluorescence collection
This paper presents an overview of development of a novel disposable plastic biochip for multiplexed clinical diagnostic applications. The disposable biochip is manufactured using a low-cost, rapid turn- around injection moulding process and consists of nine parabolic elements on a planar substrate. The optical elements are based on supercritical angle fluorescence (SAF) which provides substantial enhancement of the fluorescence collection efficiency but also confines the fluorescence detection volume strictly to the immediate proximity of the biochip surface, thereby having the potential to discriminate against background fluorescence from the analyte solution. An optical reader is also described that enables interrogation and fluorescence collection from the nine optical elements on the chip. The sensitivity of the system was determined with a biotin-avidin assay while its clinical utility was demonstrated in an assay for C-reactive protein (CRP), an inflammation marker.