Label-Free Multimetric Measurement of Molecular Binding Kinetics by Electrical Modulation of a Flexible Nanobiolayer

Most label-free techniques rely on measuring refractive index or mass change on the sensor surface. Thus, it is challenging for them to measure small molecules or enzymatic processes that only induce a minor mass change on the analyte molecules. Here, we have developed a technique by combining Surface Plasmon Resonance sensing with an Oscillating Biomolecule Layer approach (SPR-OBL) to enhance the sensitivity of traditional SPR. In addition to the inherent mass sensitivity, SPROBL is also sensitive to the charge and conformational change of the analyte; hence it overcomes the mass limit and is able to detect small molecules. We show that the multimetric SPR-OBL measurement allows for sensing any changes regarding mass, charge, and conformation, which expands the detection capability of SPR.

Automated summary

Label-free techniques often struggle to measure small molecules or enzymatic processes due to their reliance on refractive index or mass change on the sensor surface. The combination of Surface Plasmon Resonance sensing with an Oscillating Biomolecule Layer (SPR-OBL) overcomes these limitations by enhancing sensitivity to mass, charge, and conformational changes, allowing for the detection of small molecules.