Binding and adsorption events alter the local refractive index near the gold surface. SPR imaging detects those changes as shifts in the resonance signal at the corresponding image positions. Because the measurement is spatially resolved, signals can be associated with particular locations rather than treated as one averaged response. This connects an interfacial molecular event with a position-specific optical readout.
The thin gold film provides the surface where illumination can excite surface plasmons under appropriate conditions. Once excited, the resonance responds to changes close to that interface, including effects caused by binding, adsorption, or chemical reactions. This interfacial sensitivity makes the film useful for monitoring chemistry occurring at surfaces and supports measurements across patterned locations.
SPR imaging analyzes multiple defined positions within an array, allowing researchers to compare immobilized compounds or materials under the same measurement framework. Each location can produce a separate resonance response, so binding, adsorption, or reaction-related changes can be evaluated in parallel. This spatial multiplexing supports high-throughput studies of interactions, affinity, and selective sensing.
The method can monitor adsorption, molecular binding, and reaction-driven changes at a metal interface. These measurements support studies of reaction kinetics, which describe how responses change during a process, as well as affinity, which characterizes interaction strength. Selective sensing can also be investigated by comparing responses from different immobilized compounds or materials across an array.
A typical workflow places immobilized compounds or materials at defined positions on or near the sensing surface, then illuminates the thin gold film under conditions that excite surface plasmons. Researchers record resonance responses across the image and compare position-specific changes associated with binding, adsorption, or reactions. The resulting pattern helps evaluate multiple chemical conditions simultaneously.
Chemists would use SPR imaging when they need spatially resolved, parallel comparisons across an array. The approach is useful for screening immobilized compounds or materials, examining adsorption and affinity, and evaluating selective sensing responses. It can also help compare functional coatings or reaction conditions within one imaging experiment, making the resulting chemical analysis more efficient and comparative.