Related papers: Single 5-nm quantum dot detection via microtoroid …
Absorption microscopy is a powerful technique, enabling the detection of single non- fluorescent molecules at room temperature. So far, the molecular absorption has been probed optically via the attenuation of a probing laser. The…
Single-molecule microscopy has become an indispensable tool for biochemical analysis. The capability of characterizing distinct properties of individual molecules without averaging has provided us with a different perspective for the…
Ultrasensitive optical detection of nanometer-scaled particles is highly desirable for applications in early-stage diagnosis of human diseases, environmental monitoring, and homeland security, but remains extremely difficult due to ultralow…
Whispering gallery mode (WGM) microtoroid resonators are one of the most sensitive biochemical sensors in existence, capable of detecting single molecules. The main barrier for translating these devices out of the laboratory is that light…
Current optical detection schemes for single molecules require light absorption, either to produce fluorescence or direct absorption signals. This severely limits the range of molecules that can be detected, because most molecules are…
Over the last decade, single-molecule optical microscopy has become the gold-standard approach to decipher complex molecular processes in cellular environments. [1-3] Single-molecule fluorescence microscopy has several advantages such as…
Optical detection of individual nanometer-sized analytes, virus particles, and protein molecules holds great promise for understanding and control of biological samples and healthcare applications. As fluorescent labels impose restrictions…
We investigate the possibility of using dielectric microdisk resonators for the optical detection of single atoms trapped and cooled in magnetic microtraps near the surface of a substrate. The bound and evanescent fields of optical…
Detection and characterization of individual nano-scale particles, virions, and pathogens are of paramount importance to human health, homeland security, diagnostic and environmental monitoring[1]. There is a strong demand for…
Photothermal microscopy has recently complemented single molecule fluorescence microscopy by the detection of individual nano-objects in absorption. Photothermal techniques gain their superior sensitivity by exploiting a heat induced…
The ability to detect and size individual nanoparticles with high resolution is crucial to understanding behaviours of single particles and effectively using their strong size-dependent properties to develop innovative products. We report…
In nanomechanical photothermal absorption spectroscopy and microscopy, the measured substance becomes a part of the detection system itself, inducing a nanomechanical resonance frequency shift upon thermal relaxation. Suspended,…
Label-free biosensors are important tools for clinical diagnostics and for studying biology at the single molecule level. The development of optical label-free sensors has allowed extreme sensitivity, but can expose the biological sample to…
Understanding light-matter interaction at the nanoscale requires probing the optical properties of matter at the individual nano-absorber level. To this end, we have developed a nanomechanical photothermal sensing platform that can be used…
The ability to detect and identify molecules at high sensitivity without the use of labels or capture agents is important for medical diagnostics, threat identification, environmental monitoring, and basic science. Microtoroid optical…
We detect 39 nm x 10 nm gold nanorods using a microtoroid stabilized via the Pound-Drever-Hall method. Real-time detection is achieved with signal-to-noise ratios up to 12.2. These nanoparticles are a factor of three smaller in volume than…
The ability to detect single photons has become increasingly essential due to the rise of photon-based quantum computing. In this theoretical work, we propose a system consisting of a quantum dot (QD) side-coupled to a superconducting…
The photothermal heterodyne imaging technique enabled studies of individual weakly absorbing nano-objects in various environments. It uses a photo-induced change in the refractive index of the environment. Taking advantage of the dramatic…
Micro and nanoscale particles are crucial in various fields, from biomedical imaging to environmental processes. While conventional spectroscopy and microscopy methods for characterizing these particles often involve bulky equipment and…
Label-free optical microscopy through absorption or scattering spectroscopy provides fundamental insights across biology and materials science, yet its sensitivity remains fundamentally limited by photon shot noise. While recent…