Label-free detection of creatinine using nitrogen-passivated fluorescent carbon dots.

In the field of biochemistry and biosensing, the passivation of carbon dots using nitrogen dopants has attracted great attention, as this can control their photoluminescence (PL) properties and quantum yield. To date, in the fabrication of a sensing probe, the impact of the chemical composition of the passivating molecule remained unexplored. In this work, we chose a series of different nitrogen-rich precursors (such as urea, thiourea, cysteine, and glycine) and ascorbic acid to synthesize nitrogen-doped carbon dots (NCDs).

Deciphering the interaction of solvents with dual emissive carbon dots: A photoluminescence study and its response for different metal ions.

Carbon-based fluorescent quantum dots exhibited tunable photoluminescence (PL) property which is mainly dependent on its excitation wavelength which is an important factor required for optoelectronic and sensing applications. Here, we have established a microwave-based synthesis of dual emissive carbon quantum dots (CDs) using mixed-acid (HPO + HSO) and mono/disaccharides as carbon precursor. In aqueous medium, CDs showed dual emission peaks at 434 nm and 518 nm, which exhibited excitation independent fluorescence property with particle size in the range of 4-7 nm.