Toward augmenting tip-enhanced nanoscopy with optically resolved scanning probe tips

Abstract

A thorough understanding of biological species and emerging nanomaterials requires, among other efforts, their in-depth characterization through optical techniques capable of nanoresolution. Nanoscopy techniques based on tip-enhanced optical effects have gained tremendous interest over the past years, given their potential to obtain optical information with resolutions limited only by the size of a sharp probe interacting with focused light, irrespective of the illumination wavelength. Although their popularity and number of applications is rising, tip-enhanced nanoscopy (TEN) techniques still largely rely on probes that are not specifically developed for such applications, but for atomic force microscopy. This limits their potential in many regards, e.g., in terms of signal-to-noise ratio, attainable image quality, or extent of applications. We take the first steps toward next-generation TEN by demonstrating the fabrication and modeling of specialized TEN probes with known optical properties. The proposed framework is highly flexible and can be easily adjusted to be used with diverse TEN techniques, building on various concepts and phenomena, significantly augmenting their function. Probes with known optical properties could potentially enable faster and more accurate imaging via different routes, such as direct signal enhancement or facile and ultrafast optical signal modulation. We consider that the reported development can pave the way for a vast number of novel TEN imaging protocols and applications, given the many advantages that it offers.

Label-free nanoscale mapping of intracellular organelle chemistry

“…Since the maximum achievable spatial resolution in s-SNOM is related to the size of the tip of the scanning probe 20 , better resolution can be expected if a sharper tip is used, albeit to the detriment of the image signal-to-noise ratio. Developments leading to improved sensitivity in s-SNOM imaging, for example employing IR nanoantennas 8 or tip-enhancement techniques 47 , might help to alleviate this signal-to-noise issue. We also expect that experimenting with sample preparation schemes that better preserve both the morphological and chemical information would see the image resolution improve towards the ~1 nm reported in inorganic samples 48 .…”

Restoration of rotating Fourier transform ultraviolet Raman spectrum with a time sequences trigger method

“…Owing to the merits of high sensitivity, accuracy, as well as reliability, the Raman spectrum is a valuable and ubiquitous method for atmospheric CO 2 detection. [1][2][3][4][5][6][7][8][9] However, because of small Raman scattering cross section, [10][11][12][13][14] Developing Fourier Raman spectrometer is an effective resolution to realize the field measurement of atmospheric CO 2 . The RFTURS has advantages of large throughput, high resolution, and good stability, which is especially suitable for field measurement of atmospheric CO 2 .…”