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Single-molecule localization microscopy

Single-molecule localization microscopy (SMLM) is a family of fluorescence imaging techniques that surpass the diffraction limit by localizing individual molecules, with founding methods PALM, STORM, and FPALM published in 2006.

Single-molecule magnet

A single-molecule magnet (SMM) is an individual molecule that keeps its magnetization below a blocking temperature, a property first seen in the manganese complex Mn12 and later pushed to 80 K in dysprosium compounds.

Single-molecule nuclear magnetic resonance

Single-molecule nuclear magnetic resonance (NMR) detects NMR spectra from a single molecule or nanoscale ensemble instead of macroscopic samples, using diamond NV centers and magnetic resonance force microscopy.

Single-molecule transistor

A single-molecule transistor is a three-terminal electronic device whose conducting channel is a single molecule bridging source and drain electrodes, with a gate controlling the current.

Single-molecule/single-particle electrocatalysis by fluorescence microscopy

Single-molecule/single-particle electrocatalysis by fluorescence microscopy is an experimental approach using fluorogenic reporter reactions to image electrocatalysis on individual nanoparticles, revealing activity heterogeneity that ensemble measurements average away.

Single-nucleotide polymorphism

Single-nucleotide polymorphism (SNP, "snip"): a single-base DNA variant present in at least 1% of a population; roughly 4-5 million per person, cataloged in dbSNP, and used as markers in genome-wide association studies of disease and drug response.

Sep 29, 2026

Single-nucleus RNA sequencing

Single-nucleus RNA sequencing (snRNA-seq) is a transcriptomics method that profiles gene expression in individual nuclei rather than whole cells, first demonstrated in 2013 and now applied to frozen brain, kidney, heart, and tumor samples.

Single-page application

A single-page application (SPA) is a web application that loads a single HTML document, then updates content via JavaScript APIs such as Fetch, giving a desktop-like experience.

Oct 21, 2026

Single-Parent Family

A single-parent family is a household with children headed by one adult parent, most often a mother, arising mainly through divorce, separation, or births to unmarried mothers.

Single-particle cryo-electron microscopy

Single-particle cryo-electron microscopy (single-particle cryo-EM) determines the 3D structures of biological macromolecules by computationally averaging images of individual molecules frozen in vitreous ice, complementing X-ray crystallography and NMR spectroscopy.

Single-particle imaging

Single-particle imaging is an X-ray method in which femtosecond pulses from an X-ray free-electron laser record diffraction patterns from individual particles, which are merged into 3D structures without crystallization or radiation damage.

Single-particle inductively coupled plasma mass spectrometry

Single-particle inductively coupled plasma mass spectrometry (spICP-MS) is an analytical technique that counts and sizes metal-containing nanoparticles, recording each particle as a transient ion pulse.

Single-payer healthcare

Single-payer healthcare: one public entity finances and pays for universal health coverage, as in Canada's Medicare and Taiwan's National Health Insurance; defined by CBO's four features, contrasted with multipayer systems.

Single-phase electric power

Single-phase electric power, abbreviated 1φ, is alternating current distribution in which all supply voltages vary in unison, serving homes and small buildings while three-phase systems serve industrial loads.

Single-phase induction motor

A single-phase induction motor is an AC motor that runs from a single-phase supply and needs auxiliary means, such as a capacitor or shading coil, to start.

Single-photon avalanche diode

A single-photon avalanche diode (SPAD), also called a Geiger-mode avalanche photodiode, is a semiconductor photodetector that detects single photons and is used in LiDAR and PET scans.

Single-photon detector

A single-photon detector (SPD) is a device that converts individual photons into measurable electrical signals, underpinning quantum key distribution and computing, with types including SNSPDs, transition-edge sensors, and avalanche photodiodes.

Single-photon emission computed tomography

Single-photon emission computed tomography, known as SPECT or radionuclide computed tomography, is a nuclear medicine technique that reconstructs 3D images of radioactive tracer distribution using rotating gamma cameras, often to image the brain, heart, and skeleton.

Single-photon emitters in WSe2

Single-photon emitters in WSe2 are quantum emitters in monolayer tungsten diselenide, first reported in 2015, that emit one photon at a time from defect- or strain-localized excitons.

Single-photon nonlinearity

Single-photon nonlinearity is an optical effect in which one photon alters the behavior of another, the defining requirement of quantum nonlinear optics and enabling photon blockade and quantum logic gates.

Single-photon source

A single-photon source is a light source that emits one photon per excitation event, showing antibunching rather than laser-like statistics, and underlies quantum cryptography and computing.

Single-photon transistor

A single-photon transistor is a device in which a single gate photon controls the propagation of many signal photons, the optical analog of an electronic transistor at the quantum limit.

Single-player video game

Single-player video game: a game designed for one player, contrasted with multiplayer play with other real-life people. Spans genres from shooters to RPGs; early examples include OXO (1952) and Spacewar! (1962); saw renewed industry attention in 2026.