Fluorometric and colorimetric determination of hypochlorite using carbon nanodots doped with boron and nitrogen.

Abstract

Carbon nanodots doped with boron and nitrogen (BN-CDs) with an average diameter of around 11nm were prepared by a hydrothermal approach using adenine and 3-aminobenzene boronic acid as the starting materials. The atomic ratio of boron to nitrogen atomic in the BN-CDs is approximately 1:1. This indicates that a large fraction of N atoms goes lost during preparation because the B/N ratio of the precursors is about 1:6. The BN-CDs display blue fluorescence (best measured at excitation/emission wavelengths of 305/380nm) which is independent of the excitation wavelength. On exposure to hypochlorite anion, fluorescence is quenched and the color of the solutions changes from yellow to brown. Fluorescence drops linearly in the 0.1-1000μM hypochlorite concentration range. The colorimetric response, best measured as the absorbance ratioat 236/260nm, ranges from 0.3 to 4.0mM. The color changes can be readily detected visually. The probe was applied to the determination of hypochlorite in living cells and in (spiked) tap water. Graphical abstract Excitationwavelength-independent fluorescent boron and nitrogen codoped carbon nanodots (BN-CDs) were obtainedbya hydrothermal approach. The BN-CDs were usedto detect hypochlorite in wastewaterby afluorometric and colorimetric dual-readout assay.