Fluorescent carbon dots for auramine O determination and logic gate operation

•Auramine O stimulus-responsive dual-emission fluorescence individuality of the prepared CDs was investigated for the first time.•A novel fluorimetric assay of medicinal herb adulterant (auramine O) was performed.•A relative low detection limit (50 nM) was achieved.•The system was employed to design keypad lock and NOR–AND logic gate.

Carbon dots (CDs) with a fluorescence quantum yield of approximately 2.41% were prepared by simple one-step hydro-thermal synthesis of triethylenetetramine-N, N, N′, N″, N‴, N‴-hexaacetic acid (TTHA). The obtained CDs possess excitation wavelength-dependent and pH insensitive photoluminescence (PL) properties. Notably, the as-prepared CDs also exhibited unique auramine O (AO)-stimulus-responsive dual-emission fluorescence individuality, with which detection of AO using CDs has been performed through a fluorescence resonance energy transfer process. The fluorescence signals are linearly correlated with the concentration of AO over a range of 0.18–16.0 μM (R2 = 0.9989), with a limit of detection (3σ) of 54 nM. Additionally, a keypad lock and a NOR–AND logic gate was designed as well.

Graphical abstractCarbon dots (CDs) with auramine O (AO)-stimulus-responsive dual-emission fluorescence individuality were prepared via a one-step hydro-thermal treatment of triethylenetetramine-N, N, N′, N″, N‴, N‴-hexaacetic acid (TTHA) under atmospheric environment. The AO-CDs systems possess huge potentiality to develop medicinal herb adulterant sensors and logic devices.Figure optionsDownload full-size imageDownload as PowerPoint slide