Next-generation spectroscopic probe for alpha-amylase detection: Development of a potential biomarker for cancer

Abstract

A novel spectroscopic probe based on a barbituric acid-starch (ST-BA) derivative is synthesized and used to assessthe alpha-amylase activity. This derivative and its precursors are characterized by UV–Visible, fluorescence,FTIR, and 1H NMR spectroscopy. Luminescent ST-BA core contains a double bond conjugated to pyrimidine ringcarbonyl groups, yielding a notable UV–Visible absorption and fluorescence emission. Enzymatic ST-BA cleavagereveals a kinetics slower than for pristine starch, inducing new supramolecular structures with an enhancedfluorescence quantum yield. Force field minimization also supports the contribution of intra and intermolecularinteractions to ST-BA oligomer rigidification, a singularity in agreement with aggregation-induced emission.However, the decrease of UV–Visible signal reveals the chromophore competition for the photon after oligomerself-assembly. The linear spectroscopic responses support to ST-BA as a successful enzymatic activity sensor.Although these findings emphasize the ST-BA potential for qualitative enzyme analysis, further experimentalcondition studies are essential for accurate quantification.