Fig. 6. Blocked phosphine was applied in a crosslinked disulfide-based gel (state A). The addition of a thiol signal (the analyte) leads to the amplified release of phosphine and more thiol, degrading the network over time (state B), both in response to a chemical (thiol addition) and a mechanical signal (force-generated thiyl radicals as a thiol). Experiments typically conducted in 0.1 M pH 7.6 phosphate buffer.