Signal processing approach to probe chemical space for discriminating redox signatures

The discovery of discriminating molecular biomarkers often couples omics for data acquisition with advanced information processing methods for data analysis. Here, we move information processing upstream for data acquisition and report that a sample's "chemical space" can be actively probed using a tailored sequence of redox-based input signals. Specifically, we use a redox-active iridium salt (K₃IrCl₆) and an oxidative pulse-redox-relaxation input sequence to probe serum samples for chemical information. Optical and electrical output responses are collected simultaneously and analyzed using signal metrics that are sensitive to component and concentration dependent chemical information. We use the example of schizophrenia to illustrate the potential of this signal processing approach to rapidly discover discriminating signatures using simple and inexpensive instrumentation. These studies indicate that redox-probing provides an orthogonal measurement approach to accelerate biomarker discovery and further suggest a simple means to supply chemical information for the internet-of-things in medical and consumer applications.