Phase-Switching Depolymerizable Poly(carbamate) Oligomers for Signal Amplification in Quantitative Time-Based Assays

This article describes the use of poly(carbamate) oligomers that depolymerize from head-to-tail as phase-switching reagents for increasing the sensitivity of quantitative point-of-care assays that are based on measurements of time. The poly(carbamate) oligomers selectively react with hydrogen peroxide (a model analyte) and provide sensitivity by depolymerizing in the presence of the analyte to convert from water-insoluble oligomers to water-soluble products. This switching reaction enables a sample to wick through a three-dimensional paper-based microfluidic device, where the flow-through time reflects the quantity of the analyte in the sample. Oligomers as short as octamers enable quantitative detection to low nanomolar concentrations of the analyte.