Protein Binding Assessment of Immobilised Nanobody using Interferometric Nanoporous Platform
Year: 2025
Type: preprint
Abstract: Protein sensors are key tools for infectious disease diagnosis and monitoring. The medical diagnostics field is now rapidly identifying key protein markers for the detection of a range of conditions, from early cancer development through to assessment of dementia risk a decade prior to symptoms onset. Many point-of-use diagnostic tools form part of standard protocols for small molecule sensing in healthcare, including glucose and ketone body sensors. Label-free optical biosensors have emerged as reliable detection tools that provide high versatility and adaptability to detect a broad range of target analytes. Herein, we combined nanoporous anodic alumina (NAA) photonic chip technology with tailor-engineered ‘nanobodies’—recombinant variable domains of heavy-chain-only antibodies—to achieve high affinity binding to human serum albumin (HSA). We monitored dynamic shifts in the optical fingerprint of nanobody-conjugated NAA platforms in real time when these were exposed to target proteins, through reflectometric interference spectroscopy (RIfS). We performed a comprehensive characterisation of the sensing performance, where binding mechanisms were elucidated through kinetic profiles. The nanobody-conjugated NAA protein sensor demonstrated good affinity, selectivity, and sensitivity towards HSA. Our analysis revealed a sensitivity of 27.3 ± 3.2 nm µM–1 and low limit of detection of 16.3 ± 1.6 µM, which are well-below the ranges for diagnosis of medical conditions such as nephrotic syndrome. The obtained results revealed that the RIfS-based protein sensor integrated with nanobody-modified NAA has promising potential to develop point-of-care platforms for clinical diagnosis of diseases.
Institutions: Adelaide University, The University of Adelaide
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4415353488