Nondestructive Analysis of Nanomaterials using Optofluidic Assisted Raman Spectroscopy (Invited)

摘要

This talk will review and compare the different optofluidic techniques for enhancing the retrieved Raman signal of nanomaterials in liquids and aerosols. Recent progress on this front utilizing optofluidics such as photonic crystal waveguides will be discussed. Techniques and applications to combine surface enhanced with optofluidic-assisted Raman spectroscopy will be also reviewed. Challenges and future opportunities to advance optofluidics-assisted Raman spectroscopy that are carried out using portable Raman spectrometers and controlled using handheld controllers such as mobile phones will be presented. As an example, a detailed, non-destructive characterization of CdTe nanoparticles using Raman spectroscopy using concentrations of 2 mg/mL, will be highlighted. Our platform allows clear vibrational modes corresponding to the structure and interactions of the QDs to be observed. These vibrational modes include those of the CdTe core, Te defects, CdSTe interface, thiol agent and carboxylate-metal complexes. These modes are correlated with the crystallinity of the QD core, interfacial structure formed upon stabilization, QD-thiol interaction mechanisms, water solubility of the QDs and their potential bio-conjugation abilities.