Growth of Robust Carbon Nitride Films by Double Crystallization with Exceptionally Boosted Electrochemiluminescence for Visual DNA Detection

摘要

Electrochemically generated chemiluminescence (ECL) has attracted significantinterest over the past decades, ranging from fundamental studieson highly efficient electron-to-photon interconversion to practical bioassays.Nonetheless, the ECL efficiency (Φ_(ECL)) of most emitters is low, whichsignificantly hampers further development. Herein, this work reports ahighly robust carbon nitride film with unusually enhanced ECL efficiency(2256 times higher than that of the reference Ru(bpy)_3Cl_2/K_2S_2O_8). Doublecrystallization, which provides the primary interaction of carbon nitride withthe substrate and subsequent growth, plays a crucial role in the preparation.The improved ECL efficiency is ascribed to little pinholes suppressing futileco-reagent reduction, maintenance of more orbit-delocalized heptazine subunitsimproving ECL kinetics, and high transparency avoiding self-absorption.As a potential application, an ultrasensitive visual DNA biosensor by thenaked eye is further successfully developed with a linear detection range of100 pm to 1 μm and limit of detection of 27 pm (S/N = 3).