Riboflavin based conjugated biomolecule for ultrasensitive detection of nitrophenols.

Real time detection of explosive compounds in today's time is of utmost necessity due to security and severe environmental safety issues. Herein, we have synthesized a biobased conjugated molecular system from riboflavin and l-cystine utilized it for detecting picric acid in trace amount using optical sensing technique. The bioconjugate probe showed high quenching efficiency towards picric acid, which is 92.2%. In depth mechanistic study showed that ground state electrostatic interaction and inner filter effect are the factors leading to the diminishing of the probe's fluorescence intensity on addition of trace amount of the nitrophenol, picric acid. The detection limit of the conjugate is 0.37 nM which is extremely low and highly desirable for clinical applications of this system.