Rapid ultrasensitive and specific BNP biosensor with LED readout.

Biosensing for diagnostics has risen rapidly in popularity over the past decades. With the discovery of new nanomaterials and morphologies, sensitivity is being constantly improved enough for reliable detection of trace biomarkers in human samples, like serum or sweat. This precision has enabled detailed research on the efficacy of biosensors. However, current biosensors suffer from reduced speed of operation. To make better use of this sensitivity, the development of a conductometric biosensor with in-situ use of an Laser Emitting Device (LED) display can provide rapid determination of sample results, steadily pushing biosensors toward more clinical, point-of-care (POC) applications. In this research, a simple LED was used for facile optical determination and visual output of an ultrasensitive bio-signal amplification circuit was made to interface with a B-type Natriuretic Peptide (BNP) biosensor. Tuning circuit gain enables an elegant method for adjustable separation of concentrations into 3 discrete categories: sub-threshold, analog, and saturation regions. These regions corresponded to 0 < [C] < 500 pg/mL (25, 100, 250 pg/mL, LED off), 500 < [C] < 1000 pg/mL (LED varying intensity), and 1000 pg/mL < [C] (LED full intensity). System efficacy was tested using human blood serum samples from University of Pittsburgh Medical Center patients, which were able to be accurately detected and sorted for rapid low cost and power. determination without need for complex digital elements. Additional specificity testing suggests insignificant impact of non-target biomarkers.