Fluorescent Polyaniline Nanoclips (PANCs): A Highly Sensitive and Selective Chemical Sensor for the Detection of Hg (II) Ions in Aqueous Media

Novel fluorescent biosensor constructed by polyaniline nanoclips (PANCs) embedded with FAM‐ssDNA for precise detection of mercury ions (Hg2+). The PANCs was adapted to fabricate by an oxidative template method and characterized via various analytical techniques, namely scanning Electron Microscope (SEM), powder X‐ray Diffraction (XRD), Fourier transform infrared (FT‐IR), circular dichroism (CD spectra) and fluorescence spectroscopy. Based on the strong adsorption property of PANCs was despite a strong quenching of FAM‐ssDNA fluorescence. Furthermore, FAM‐ssDNA was a strong surface absorption on the surface of polyaniline nanoclips through non‐covalent interaction. The fluorescence intensity decreased denotes the electrons transfer from the nitrogen in polyaniline nanoclips to fluorophore of ssDNA as well as may be photo‐induced electron transfer (PET). Meanwhile, the addition of mercury ion into a detection probe, which increases the fluorescence intensity due to the desorption. However, the strong binding ability between mercury ion and thymine of FAM‐ss DNA leads to form T‐Hg2+‐T duplex mismatch. These results indicate the significant fluorescence intensity was improved and the Hg2+ sensor was developed. Interestingly, the sensing probe reached the detection limit at 4 nM with rapid response and showed high selectivity towards mercury ions compared to other metal ions. Furthermore, the polyaniline nanoclips were potentially applied for the real samples. Novel fluorescent biosensor constructed by polyaniline nanoclips (PANCs) embedded with FAM‐ssDNA for precise detection of mercury ions (Hg2+). The PANCs was adapted to fabricate by an oxidative template method and characterized via various analytical techniques, namely SEM, XRD, FT‐IR, CD spectra and fluorescence spectroscopy. The sensing probe reached the detection limit at 4 nM with rapid response and showed high selectivity towards mercury ions compared to other metal ions.