N-doped carbon dots/H2O2 chemiluminescence system for selective detection of Fe2+ ion in environmental samples

The nitrogen doped carbon dots (N-CDs) produces strong chemiluminescence (CL)-emission due to hydroxyl radical ( • OH) induced electron-hole transition in N-CDs. The Fe 2+ has the ability to generate • OH from available hydrogen peroxide (H 2 O 2 ). Therefore, a pre-mixed N-CDs/H 2 O 2 solution was utilized for selective quantification of Fe 2+ in solution via CL-emission. A linear increase in the CL-emission intensity was observed within increase in Fe 2+ concentration. The N-CDs/H 2 O 2 system enabled the detection of Fe 2+ up to lower concentration of 0.2 × 10 −9 M with a linear dynamic range of 1.0 × 10 −9 –1.0 × 10 −6 M. Significantly, no CL-emission was observed when other divalent cations , Al 3+ , Fe 3+ , or Cr 3+ were injected to this system. Moreover, no interference was observed when a mixed solution of Fe 2+ and other cations were introduced to N-CDs/H 2 O 2 . The practical evaluation of N-CDs/H 2 O 2 system was demonstrated for detection of Fe 2+ in tap, lotus pond, and canal water samples. The easy detection, high sensitivity, and selectivity make this method a significant tool for analysis of Fe 2+ in solution.