Tunable photoluminescence studies based on blue-emissive carbon dots and sequential determination of Fe(III) and pyrophosphate ions

Fluorescence has been well documented and the optical feature of carbon dots generates considerable interests. Here the nitrogen-doped carbon dots with a relative quantum yield of 25% have been prepared. It displays stable blue emission based on the excitation at 355 nm. The carbon nanomaterial is highly dispersible in aqueous solution and can be employed as an effective optical probe for label-free detection of Fe 3+ (0.87 μM) via a switched off change. Additionally, such sensing nanoplatform can be recovered in the presence of pyrophosphate (PPi) and an “off-on” process has been identified. It is expected that this on-off-on strategy will allow new possibilities for developing efficient sensors in industrial fields.