Double-side effect of B/C ratio on BDD electrode detection for heavy metal ion in water

A Nanograss Boron and Nitrogen Co-Doped Diamond Sensor Produced via High-Temperature Annealing for the Detection of Cadmium Ions

The high-performance determination of heavy metal ions (Cd2+) in water sources is significant for the protection of public health and safety. We have developed a novel sensor of nanograss boron and nitrogen co-doped diamond (NGBND) to detect Cd2+ using a simple method without any masks or reactive ion etching. The NGBND electrode is constructed based on the co-doped diamond growth mode and the removal of the non-diamond carbon (NDC) from the NGBND/NDC composite. Both the enlarged surface area and enhanced electrochemical performance of the NGBND film are achievable. Scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse anodic stripping voltammetry (DPASV) were used to characterize the NGBND electrodes. Furthermore, we used a finite element numerical method to research the current density near the tip of NGBND. The NGBND sensor exhibits significant advantages for detecting trace Cd2+ via DPASV. A broad linear range of 1 to 100 μg L-1 with a low detection limit of 0.28 μg L-1 was achieved. The successful application of this Cd2+ sensor indicates considerable promise for the sensitive detection of heavy metal ions.

Nano-Needle Boron-Doped Diamond Film with High Electrochemical Performance of Detecting Lead Ions

Nano-needle boron-doped diamond (NNBDD) films increase their performance when used as electrodes in the determination of Pb2+. We develop a simple and economical route to produce NNBDD based on the investigation of the diamond growth mode and the ratio of diamond to non-diamond carbon without involving any templates. An enhancement in surface area is achievable for NNBDD film. The NNBDD electrodes are characterized through scanning electron microscopy, Raman spectroscopy, X-ray diffraction, cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse anodic stripping voltammetry (DPASV). Furthermore, we use a finite-element numerical method to research the prospects of tip-enhanced electric fields for sensitive detection at low Pb2+ concentrations. The NNBDD exhibits significant advantages and great electrical conductivity and is applied to detect trace Pb2+ through DPASV. Under pre-deposition accumulation conditions, a wide linear range from 1 to 80 µgL-1 is achieved. A superior detection limit of 0.32 µgL-1 is achieved for Pb2+, which indicates great potential for the sensitive detection of heavy metal ions.

N. NK, Budagumpi S, Kumar Bose S, P. S, Palakollu VN. Tuning the Surface Functionality of Fe3O4 for Sensitive and Selective Detection of Heavy Metal Ions

The functionalization of materials for ultrasensitive detection of heavy metal ions (HMIs) in the environment is crucial. Herewith, we have functionalized inexpensive and environmentally friendly Fe₃O₄ nanoparticles with D-valine (Fe₃O₄-D-Val) by a simple co-precipitation synthetic approach characterized by XRD, FE-SEM, and FTIR spectroscopy. The Fe₃O₄-D-Val sensor was used for the ultrasensitive detection of Cd⁺², Pb⁺², and Cu⁺² in water samples. This sensor shows a very low detection limit of 11.29, 4.59, and 20.07 nM for Cd⁺², Pb⁺², and Cu⁺², respectively. The detection limits are much lower than the values suggested by the world health Organization. The real water samples were also analyzed using the developed sensor.

Diamond-Based Electrodes for Detection of Metal Ions and Anions

Diamond electrodes have long been a well-known candidate in electrochemical analyte detection. Nano- and micro-level modifications on the diamond electrodes can lead to diverse analytical applications. Doping of crystalline diamond allows the fabrication of suitable electrodes towards specific analyte monitoring. In particular, boron-doped diamond (BDD) electrodes have been reported for metal ions, anions, biomolecules, drugs, beverage hazards, pesticides, organic molecules, dyes, growth stimulant, etc., with exceptional performance in discriminations. Therefore, numerous reviews on the diamond electrode-based sensory utilities towards the specified analyte quantifications were published by many researchers. However, reviews on the nanodiamond-based electrodes for metal ions and anions are still not readily available nowadays. To advance the development of diamond electrodes towards the detection of diverse metal ions and anions, it is essential to provide clear and focused information on the diamond electrode synthesis, structure, and electrical properties. This review provides indispensable information on the diamond-based electrodes towards the determination of metal ions and anions.