Novel Optical Scanning Probe Microscope for Biomedical Chemical Imaging with Ultra-High Spatial Resolution and Chemical Sensitivity

Abstract: Understanding molecular mechanisms of diseases and manipulating them to achieve cure constitutes one of the "holy Grail" of biomedical science. Infectious (and parasitic) diseases are responsible for ~30% of premature deaths, especially in low- and middle-income countries. Studies of the pathogenic agents

require high-resolution and high-sensitivity microscopy and spectroscopy equipment, ideally capable of detecting single molecules of interest (i.e., DNA bases, proteins on viral capsids, etc.). Scanning near-field optical microscopy (SNOM) combined with near-field nano-spectroscopy- Tip-Enhanced Raman spectroscopy

(TERS) is the best technology for visualization of such nanoscale details. However, the spatial resolution and chemical sensitivity levels are currently insufficient to detect and identify single molecules in an ambient environment (air or liquid). Current methods for the identification of infectious agents rely on traditional

methods that include growing of bacteria and fungi, isolation of viruses in cell culture, and then identification of the agent biochemically, antigenically, or genetically (which require the availability of specific antibodies for ELISA tests and specific DNA primers for PCR). These methods make the identification of newly emerging

pathogens particularly difficult. New approaches to diagnostics are overdue. Actoprobe LLC proposes such an approach: to develop, validate, and commercialize a novel class of probes for Scanning Probe Microscopy (SPM) based on silicon nitride photonics with a diode laser, a pulse compressor, and a detector, all inside the SPM

probe. The ultimate goal is to dramatically (>10X) increase SNOM's sensitivity and spatial resolution for rapid identification of infectious agents. With its strong research experience and expertise in TERS and SNOM, Actoprobe is in an ideal position to address this technical challenge. This new TERS tool's capabilities will allow

studying the biochemical components, morphology, and nanomechanical structures of viruses, bacteria, and fungi at the single-molecule level, substantially improving early infectious disease detection and identification. We expect the proposed technology will enable substantially improved early pathogenic disease

agent detection and lead to a marketable, cost-effective diagnostic/identification tool. Our primary customers will be medical laboratories and clinical research institutions. Phase I will prove the technical feasibility of developing the ultrasensitive optical SPM probes and testing these probes on several non-pathogenic viruses.