We aim to develop a benchtop imaging device to quantitatively measure stress biomarkers like HSP90 on a biochip. Measurement of HSP90 is based on the masking of fluorescence of Streptavidin conjugated Quantum dots (Sav-QDs) when HSP90 attaches to it. The higher the masking of fluorescence, the higher the HSP90 concentration. Measurement of fluorescence is done by a custom-built optical device. The goal in this work was to demonstrate a testing system which is handy to use in the field, cheaper and with a simplified readout system for the users. Sav-QDs are fixed on nitrocellulose coated glass slides (NC slides). A biotinylated antibody is attached to Sav-QD. When HSP90 interacts with the antibody it causes masking of fluorescence, which is dependent on the concentration of HSP90 in serum. The imaging device developed for measurement is based on a CMOS sensor. It uses narrow bandpass filters, optically eliminating fluorescence produced by the background. Analysis of the results shows that these agree well with those of standard laboratory equipment using a photomultiplier tube (PMT) scanner to detect HSP90 in the nanomolar range. Results from the work show that the used approach is promising for developing a multifunctional, robust, and point-of-care detection system for stress biomarkers.
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