Engineering Nano-Au-Based Sensor Arrays for Identification of Multiple Ni(II) Complexes in Water Samples

Area of Science:

• Environmental Chemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Traditional methods struggle to differentiate diverse nickel (Ni(II)) species, hindering effective water remediation.
• Nickel speciation is crucial for understanding its environmental impact and designing removal strategies.

Purpose of the Study:

• To develop an advanced colorimetric sensor array for discriminating various Ni(II) species in water.
• To enable accurate Ni(II) speciation for improved water decontamination and toxic metal detection.

Main Methods:

• Utilized a sensor array of gold nanoparticles (Au NPs) modified with N-acetyl-l-cysteine (NAC), tributylhexadecylphosphonium bromide (THPB), and a mixture of 3-mercapto-1-propanesulfonic acid and adenosine monophosphate (MPS/AMP).
• Investigated interactions with twelve classical Ni(II) species, analyzing UV-vis spectral shifts and Au NP aggregation behaviors.
• Employed multivariate analysis, including principal component analysis (PCA), for species discrimination and mechanism elucidation.

Main Results:

• The sensor array demonstrated distinct colorimetric responses to different Ni(II) species due to diverse aggregation behaviors.
• Unambiguous discrimination of individual and mixed Ni(II) species was achieved in simulated and real water samples with high selectivity.
• Achieved high sensitivity with detection limits ranging from 4.2 to 10.5 μM for target Ni(II) species.

Conclusions:

• The developed colorimetric sensor array effectively discriminates complex Ni(II) species, overcoming limitations of traditional methods.
• PCA analysis indicated that coordination plays a dominant role in the sensor's response to different Ni(II) species.
• This technology offers a promising tool for rational water decontamination design and the development of novel toxic metal discrimination methods.