Ultrasensitive Detection and In Situ Imaging of Analytes on Graphene Oxide Analogues Using Enhanced Raman...

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Ultrasensitive detection of trace molecules is crucial for various scientific applications.
• Graphene-based materials offer unique properties for chemical sensing and spectroscopy.
• Confocal Raman microscopy provides molecular information but often requires enhancement for trace detection.

Purpose of the Study:

• To develop an ultrasensitive detection method for rhodamine (R6G) molecules in aqueous solutions.
• To investigate the use of algorithm-improved confocal Raman microscopy (ai-CRM) combined with 2D substrates.
• To explore the adsorption kinetics and spatial distribution of trace adsorbing molecules.

Main Methods:

• Utilized algorithm-improved confocal Raman microscopy (ai-CRM) for enhanced signal detection.
• Employed chemically enhanced two-dimensional substrates, including laser-induced reduced graphene oxide and UV/ozone-oxidized graphene.
• Developed a protocol for noninvasive Raman imaging after molecule adsorption.

Main Results:

• Achieved a limit of detection (LOD) of 5 × 10^-10 M for R6G using ai-CRM on reduced graphene oxide.
• Demonstrated an equivalent subnanomolar LOD on a UV/ozone-oxidized graphene analogue.
• Successfully studied adsorption kinetics and imaged the spatial distribution of adsorbed R6G molecules.

Conclusions:

• Algorithm-improved graphene-enhanced Raman spectroscopy is a facile and powerful method for ultrasensitive molecule detection.
• The developed technique enables effective detection, imaging, and quantification of trace adsorbing molecules.
• This approach shows strong potential for application with various 2D substrates in analytical sensing.