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 Fe2+ has the ability to generate •OH from available hydrogen peroxide (H2O2). Therefore, a pre-mixed N-CDs/H2O2 solution was utilized for selective quantification of Fe2+ in solution via CL-emission. A linear increase in the CL-emission intensity was observed within increase in Fe2+ concentration. The N-CDs/H2O2 system enabled the detection of Fe2+ 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, Al3+, Fe3+, or Cr3+ were injected to this system. Moreover, no interference was observed when a mixed solution of Fe2+ and other cations were introduced to N-CDs/H2O2. The practical evaluation of N-CDs/H2O2 system was demonstrated for detection of Fe2+ in tap, lotus pond, and canal water samples. The easy detection, high sensitivity, and selectivity make this method a significant tool for analysis of Fe2+ in solution.