Detection Of Nickel Ions Research Articles

Nickel-Catcher-Doped Zwitterionic Hydrogel Coating on Nickel-Titanium Alloy Toward Capture and Detection of Nickel Ions.

Nickel–titanium (NiTi) alloys show broad applicability in biomedical fields. However, the unexpected aggregation of bacteria and the corrosion of body fluid on NiTi-based medical devices often lead to the leakage of nickel ions, resulting in inevitable allergic and cytotoxic activities. Therefore, the capture and detection of nickel ions are important to avoid serious adverse reactions caused by NiTi-based medical devices. Herein, we presented a nickel ion capture strategy by the combination of zwitterionic hydrogels as anti-bacteria layers and carbon disulfide (CS2) components as nickel-catchers (Ni-catchers). On the one hand, the hydration layer of zwitterionic hydrogel can efficiently inhibit bacteria adhesion and reduce nickel ions leakage from NiTi corrosion. On the other hand, Ni-catchers can capture leaked nickel ions from NiTi alloy actively by chelation reaction. Therefore, this strategy shows great capabilities in resisting bacteria adhesion and capturing nickel ions, providing the potential possibility for the detection of nickel ion leakage for implantable biomedical materials and devices.

Centrifugal Paperfluidic Platform for Accelerated Distance-Based Colorimetric Signal Readout.

Distance-based readout is one of the most user-friendly and simple colorimetric signaling methods widely applied for paper-based analytical devices (PADs). This work presents the integration of distance readout PADs into a centrifugal platform enabling affordable, rapid, and sample volume-independent colorimetric assays. Centrifugally assisted distance-based PADs (CD-PADs) eliminate the requirement to use micropipets for sample introduction and reduce the overall time for distance-based assays. All device fabrication steps were performed through computer-controlled print, cut, and laminate (PCL) techniques oriented toward mass production. The inexpensive centrifugal platform was built on a recycled DVD player combined with an open source microcomputer (Arduino). Assay protocols, including rotational velocity and rotation time, were optimized to obtain a maximum dynamic range and reproducible results for sample volume metering (coefficient of variation 3.62%). A colorimetric Ni2+ assay chosen to demonstrate measurements on CD-PADs allowed the detection of nickel ions (Ni2+) with naked-eye interpretation within 1.5 min and a limit of detection (LOD) of 44.1 ng of Ni2+, which to the best of our knowledge is the lowest value reported for a distance-based Ni2+ assay.

Nickel-selective coated disk electrode based on carbon nanotube composite modified with a new Schiff base

A coated disk polyvinyl chloride (PVC) matrix membrane ion-selective electrode for detection of nickel ion was fabricated based on multiwalled carbon nanotube composite modified with bis(2-hydroxyacetophenone)-1,2-propandiimine (BHAPN) as ionophore. The electrode showed a Nernstian slope of 29.7 ± 0.45 mV decade−1 over a wide concentration range of 9.1 × 10−7 to 2.0 × 10−2 mol L−1 of Ni(NO3)2 with detection limit of 3.2 × 10−7 mol L−1. This electrode was applicable in the pH range of 3.0–7.9 and had a short response time of approximately 6.0 s. The electrode exhibited good selectivity for Ni(II) relative to other metal ions. The use of multiwalled carbon nanotube (MWCNTs) in a polymer matrix improves the linear range and sensitivity of the electrode. The practical analytical utility of the electrode was demonstrated by the using it as an indicator electrode for potentiometric titration of Ni(II) ions with EDTA solution.