Hydrothermal Synthesis of Boron Nitride Quantum Dots/Poly(Luminol) Nanocomposite for Selective Detection of Ascorbic Acid

Boron nitride quantum dots (BNQDs) were synthesized hydrothermally using boric acid and urea. High-resolution transmission electron microscopy (HR-TEM) analysis confirmed the formation of BN quantum dots with the lattice size of 0.227 nm. Fourier-transform infrared (FT-IR) and Ultraviolet–visible (UV-Vis) spectroscopies revealed the B-N, O-H and N-H bond formation in the BNQDs and the maximum absorption wavelength at 269 nm. BNQDs exhibited strong fluorescence emission at a wavelength of 330 nm. Furthermore, BNQDs were coated onto a glassy carbon electrode (GCE). Followed by, poly(luminol) (Plu) was electrochemically deposited onto BNQDs/GCE from 0.1 M H2SO4 containing 0.5 mM luminol in order to prepare nanocomposite (hybrid film) coated electrode with improved stability and electrochemical activity. Due to unique nature and synergetic effect between BNQDs and Poly(luminol), as-prepared hybrid Plu/BNQDs film coated GCE showed improved electrocatalytic activity for vitamin C (ascorbic acid, AA) oxidation at 0.2 V. The calibration graph was obtained from 10 to 100 μM AA by amperometry and limit of detection (LOD) was found to be 1.107 μM. The interference effects were also carried out in the presence of uric acid (UA), dopamine (DA) and glucose (Glu). Interestingly, UA, DA and Glu did not produce significant responses on the Plu/BNQDs/GCE which indicated good selectivity of the sensor for AA. Moreover, Plu/BNQDs/GCE based sensor showed reproducible and repeatable analytical performances. We propose that the Plu/BNQDs based hybrid film can be used as a selective sensor probe for the detection of the AA.