Selective sensing of adenosine monophosphate (AMP) by a calix[6]triazolium-based colorimetric sensing ensemble

Since adenosine monophosphate (AMP) is closely related to many diseases, the measurement of AMP is important for the diagnosis and treatment of related diseases. Among the AMP sensors reported thus far, sensors that selectively recognize AMP, not ADP or ATP, are rare, and complex experimental procedures and additional instruments are required for AMP recognition. We developed a colorimetric chemosensor using calix[6]triazolium (CT6) and intended to use it for the simple and rapid detection of AMP. Colorimetric AMP detection was established through an indicator displacement assay (IDA) in which CT6 and Brooker's merocyanine (BM) were used as receptors and indicators, respectively. The change in the absorption spectrum and color of BM showed that the binding affinity of CT6 to AMP conferred high selectivity to the developed colorimetric chemosensor. The developed IDA-based chemosensor was extended to fabricate a paper-based colorimetric device for visual measurement, and the paper-based device exhibited a selective response to AMP through a definite color change from yellow to magenta. This paper-based colorimetric device shows growth potential for onsite visual measurement of AMP.