Sensitive and quantitative biosensing technique based on NV centres-doped nanodiamonds applied to lateral flow assays.

This paper presents the development of an innovative biomarker detection technology based on NV centres. In order to provide initial proofs of concept for the technique, we applied this detection technique to Lateral Flow Assays (LFA) through the use of NV-doped functionalised nanodiamonds (ND) as LFA labels. The remarkable properties of NV centres in diamond enable a sensitive and quantitative detection of biomarkers with an LFA label that is robust to external perturbation, easy to handle and functionalisable for a wide range of targets. The aim of NV-based LFA is to combine the advantages of the most widely used LFA - i.e. high speed, simplicity and low cost - with quantitative and highly sensitive measurements in a large detection range, from pg/mL limit of detection to mg/mL. Such detection could be of great interest in a variety of applications where simple but sensitive detection is required, for e.g. biomedical, agri-food or ecotoxicology diagnostics. NV-doped nanodiamonds have already shown promise as alternative labels in LFA, yet lack quantitative comparison with conventional markers. This study addresses this gap by validating an NV-based LFA setup for cancer antigen detection and providing a first experimental comparison with standard LFA labels.