A coronene diimide based radical anion for detection of picomolar H 2 O 2 : a biochemical assay for detection of picomolar glucose in aqueous medium.

Coronene diimide functionalized with 4-(2-nitrovinyl)phenyl (CDI 2) serves as a precursor for generating a stable radical anion (CDI 2˙ - ) using H 2 S as a reductant in 40% H 2 O-THF solution in the NIR region with stability up to >50 min. The optical, cyclic voltammetry (CV), current-voltage ( I - V ) and electron paramagnetic resonance (EPR) studies revealed the formation of the radical anion (CDI 2˙ - ). The addition of a strong oxidant NOBF 4 quenches the radical anion (CDI 2˙ - ). The aggregation studies revealed that CDI 2 exists in the aggregated state in 40% H 2 O-THF solution, which points to the possibility of stabilization of the radical anion in the aggregates. The radical anion (CDI 2˙ - ) was explored for the detection of 58.27 pM H 2 O 2 in aqueous medium with the naked eye colour change from green to light yellow. The biochemical assay involving the radical anion (CDI 2˙ - ) and glucose oxidase (GOx) enzyme can be used for the detection of 16 pM (UV-vis method) and 82.4 pM (fluorescence method) glucose. The naked eye colour change from green to light yellow (daylight) and a colorless non-fluorescent solution to a green fluorescent solution (365 nm) allow the detection of 1 nM glucose.