Quaternary ammonium-functionalized carbon dots for sensitive and selective detection of 2,4,6-trinitrophenol in aqueous medium.

A new fluorescence nanosensor for sensitive and selective 2,4,6-trinitrophenol (TNP) determination is reported based on (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CTA) functionalized carbon dots (CTA-CDs). Carboxymethyl cellulose sodium (CMC)-4,7,10-trioxa-1,13-tridecanediamine (TTDDA) mixture was heated to prepare passivated CDs. Then CTA was grafted onto the surface of the passivated CDs by esterification reaction to form quaternary ammonium-functionalized CTA-CDs. Therefore, the CTA-CDs are used as a sensor for the detection of 2,4,6-trinitrophenol (TNP) in water via molecular interactions (electrostatic, π−π, and hydrogen bonding interactions) between TNP and CTA-CDs. A limit of detection of the CTA-CDs for TNP in aqueous solution is 7.04 × 10 −7  mol/L, which is lower than that of the passivated CDs for TNP (3.03 × 10 −6  mol/L). In addition, compared with various organic reagents, the CTA-CDs exhibit significantly sensitive and selective sensing towards TNP in aqueous medium. [ABSTRACT FROM AUTHOR]