Biochip readout system for point-of-care applications

A new low cost biochip readout system based on total internal reflection fluorescence (TIRF) including microfluidics is presented. The system is suitable for point-of-care diagnostics employing disposable substrates made of polymer foils producible at very low costs. Results for the reader sensitivity and dynamic range in comparison to state of the art readers are presented. The sensitivity is comparable to laser scanner systems developed for lab applications, although the newly developed TIRF system is built up much simpler and low cost substrates are used. The dynamic range and the on chip homogeneity were investigated. As an example for future POC applications, an immunoassay for the inflammation parameter C-reactive protein (CRP) is investigated. The sensitivity of these assays is in the range of 1 ng/ml, being sufficient for many parameters of clinical relevance.