Exploring the interactions between gold nanoparticles and analytes through surface-assisted laser...

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Functionalized gold nanoparticles (Au NPs) are sensitive to chemical interactions.
• Understanding analyte-induced changes in nanoparticle properties is crucial for developing new detection methods.

Purpose of the Study:

• To investigate the chemical reactions of functionalized Au NPs with Hg(2+) ions and H(2)O(2).
• To demonstrate the utility of SALDI-MS for studying analyte-induced surface property changes in nanoparticles.

Main Methods:

• Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) was employed.
• Analyzed Hg(2+)-induced aggregation of 2,6-pyridinedicarboxylic acid (PDCA) and mercaptopropionic acid (MPA) functionalized Au NPs.
• Investigated H(2)O(2)-induced fluorescence quenching of 11-mercaptoundecanoic acid (11-MUA) functionalized Au Nanoparticles (NDs).

Main Results:

• PDCA-Hg(2+)-MPA coordination caused Au NP aggregation.
• Formation of 11-MUA disulfide compounds led to H(2)O(2)-induced fluorescence quenching.
• SALDI-MS demonstrated selectivity and sensitivity for Hg(2+) (LOD 300 nM) and H(2)O(2) (LOD 250 µM).
• Low spot-to-spot variation (<18%) confirmed method reliability.

Conclusions:

• SALDI-MS provides strong evidence for chemical reactions involving functionalized nanoparticles and analytes.
• The study highlights SALDI-MS as a powerful tool for sensitive and selective detection of Hg(2+) and H(2)O(2).
• SALDI-MS can effectively probe analyte-induced alterations in nanoparticle surface chemistry.