Hybrid Boron Nitride/N-Doped\nGraphene Quantum Dots\nfor Specific and Picomolar Electrochemical Detection of Pb(II) Ions

The growth in various industrial and economic sectors\nhas led to\nthe pollution of the world’s water resources to a considerable\nextent. Many harmful contaminants enter water sources consistently,\nleading to environmental damage, a major concern. One of the widespread\npollutants are heavy metal ions (HMIs), such as ions of lead, mercury,\ncadmium, and arsenic, which are highly toxic even at very low concentrations\nof parts per billion (ppb) levels; they pose severe threats to both\nhumans and other living organisms. This has headed to the stage where\na constant monitoring system of environmental water resources for\nHMIs has become imperative. In this study, we have made a hybrid quantum\ndot material made of boron nitride (BN) and nitrogen-doped graphene\n(Hyb-BNQD-NGQD) from bulk BN and polyaniline (PANI), which exhibited\nspecific sensing of Pb(II) ions. This material exhibited exceptional\nselectivity and sensitivity toward Pb(II) ions and a higher current\nresponse than the unmodified glassy carbon electrode, BNQDs, NGQDs,\nand the physical mixture of BNQDs and NGQDs with a remarkable detection\nlimit of 1 × 10<sup>–12</sup> M (0.2 ppt). Hyb-BNQD-NGQD\nexhibited selectivity for Pb(II) ions in the presence of multiple\nother potential interfering metal ions and maintained a similar current\nresponse (≤5% variation) in wastewater samples without any\ninterference from other contaminants, highlighting its remarkable\nspecific sensing capability.