Noncontact tip-enhanced Raman spectroscopy for nanomaterials and biomedical applications

Nanoscale Adv. 2019 Aug 19;1(9):3392-3399. doi: 10.1039/c9na00322c. eCollection 2019 Sep 11.

Abstract

Tip-enhanced Raman spectroscopy (TERS) has been established as one the most efficient analytical techniques for probing vibrational states with nanoscale resolution. While TERS may be a source of unique information about chemical structure and interactions, it has a limited use for materials with rough or sticky surfaces. Development of the TERS approach utilizing a non-contact scanning probe microscopy mode can significantly extend the number of applications. Here we demonstrate a proof of the concept and feasibility of a non-contact TERS approach and test it on various materials. Our experiments show that non-contact TERS can provide 10 nm spatial resolution and a Raman signal enhancement factor of 105, making it very promising for chemical imaging of materials with high aspect ratio surface patterns and biomaterials.