A single-molecule mechanoanalytical real-time sensing device (SMART) comprising a molecular trawl and a DNA stem-loop structure that serves as a molecular dipstick, said trawl and said DNA stem-loop structure anchored by handles to two optically-trapped bead templates; said molecular trawl comprising multiple analyte recognition elements that exist in each of two separate DNA (pair) strands that act as two pincers, said pincers each having a nucleobase capable of catching an analyte in a media; said DNA stem-loop structure comprising a plurality of nucleotides in said loop and multiple base pairs in said stem; and wherein said DNA stem-loop is located generally opposite to said molecular trawl that is capable of reporting an amount of bound analyte target via mechanochemical transient events.