In-situ and ultrasensitive detection of mercury (II) ions (Hg2+) using the localized surface plasmon resonance (LSPR) nanosensor and the microfluidic chip

• Published in: Sensors and actuators. A. Physical. 2023-01, Vol.349, p.114074, Article 114074
• Main Authors: Zhang, Wenjia, Liu, Guohua, Bi, Jinqiang, Bao, Kexin, Wang, Peiren
• Format: Article
• Language: English
• Subjects: Dark field spectroscopy; Localized surface plasmon resonance (LSPR); Mercury (II) ions (Hg2+); Microfluidic chip; The core-satellite nanostructure
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2022.114074

Mercury is one of the most dangerous heavy metals due to its extreme toxicity to both humans and the biosphere. In this work, an in-situ and ultrasensitive method for the detection of mercury (II) ions (Hg2+) using the dark-field microspectroscopy-based localized surface plasmon resonance (LSPR) nanosensor is demonstrated. In our homemade high-throughput microfluidic chip, the fixed nanorods and the free small gold nanospheres combine to form the core-satellite structures with the help of T- Hg2+-T chemical coordination. Such a process results in a spectral red shift due to plasmonic coupling, which allows us to reach a picomolar detection limit and a linear response range from 10 pM to 10 µM. In addition, our LSPR nanosensor has excellent selectivity and no interference for the detection of Hg2+, which was evaluated by monitoring responses to different heavy metal ions (Pb2+, Cd2+, Cr2+, Ni2+, and Cu2+) and their mixed samples. Our sensor platform's effectiveness offers a practical method for detecting traces of Hg2+ in real-life water samples. [Display omitted] •Dark-field microspectroscopy and microfluidic chips based nanosensor for ultrasensitive Hg2+ detection was designed.•Specific oligonucleotides functionalized core-satellite nanostructure were used as imaging and recognition probes.•The LSPR nanosensor exhibited excellent LOD (2.7 pM) and a wide detection range toward Hg2+ detection.•Our sensing system could be able to achieve parallel high-throughput detection of multiple analytes.