Amplification of Refractometric Biosensor Response through Biomineralization of Metal–Organic Framework Nanocrystals

Abstract

Plasmonic biosensors based on the refractive index sensitivity of localized surface plasmon resonance (LSPR) are highly promising for on‐chip and point‐of‐care diagnostics. In particular, plasmonic biosensors that rely on artificial antibodies are highly attractive for applications in resource‐limited settings due to the excellent thermal, chemical, and environmental stability of these biorecognition elements. In this work, a universal LSPR response amplification strategy based on the biomineralization of a metal–organic framework (MOF) on the captured analyte proteins is demonstrated. The amplification relies on the differential ability of abiotic recognition elements and captured biomolecules to induce biomineralization of a MOF. The rapid amplification process (less than 10 min) demonstrated here results in nearly 100% higher sensitivity and three times lower limit of detection compared to the innate sensor. The amplification approach can be broadly applied to a wide variety of bioanalytes and can be rapidly implemented in real‐world conditions without compromising the assay time or reusability of the plasmonic biochip.