Ultrasensitive Detection and In Situ Imaging of Analytes on Graphene Oxide Analogues Using Enhanced Raman Spectroscopy.
Sachin NairJun GaoCees OttoMichael H G DuitsFrieder MugelePublished in: Analytical chemistry (2021)
We demonstrate how algorithm-improved confocal Raman microscopy (ai-CRM), in combination with chemical enhancement by two-dimensional substrates, can be used as an ultrasensitive detection method for rhodamine (R6G) molecules adsorbed from aqueous solutions. After developing a protocol for laser-induced reduction of graphene oxide, followed by noninvasive Raman imaging, a limit of detection (LOD) of 5 × 10-10 M R6G was achieved using ai-CRM. An equivalent subnanomolar LOD was also achieved on another graphene oxide analogue -UV/ozone-oxidized graphene. These record-breaking detection capabilities also enabled us to study the adsorption kinetics and image the spatial distribution of the adsorbed R6G. These findings indicate a strong potential for algorithm-improved graphene-enhanced Raman spectroscopy as a facile method for detecting, imaging, and quantifying trace amounts of adsorbing molecules on a variety of 2D substrates.
Keyphrases
- raman spectroscopy
- label free
- high resolution
- loop mediated isothermal amplification
- deep learning
- real time pcr
- artificial intelligence
- gold nanoparticles
- machine learning
- quantum dots
- randomized controlled trial
- room temperature
- single molecule
- aqueous solution
- high throughput
- heavy metals
- climate change
- molecular dynamics simulations