A lot of work has been done to improve point-of-care technologies to make them easier to perform, cheaper, and more sensitive and specific. However, despite these efforts, there is still no platform technology that can enable sub-pg/mL detection in a facile manner. Technologies that can achieve this promise in-home monitoring of treatment, early-stage detection of disease and more robust population level screening. We are developing nanotechnology solutions towards this goal.
We seek to discover and engineer nanomaterials with increased functionality for use in diagnostic applications. We are interested in how nanomaterial design, construction and functionalisation can be performed by incorporating synthetic and biologically derived components. We then explore how these can enable better performance in a variety of sensing systems that incorporate plasmonic, SERS and fluorescence-based detection.
We design new diagnostic architectures that benefit from creating nanoparticles with added functionalities that enable us to take advantage of computational methods to improve diagnostic performance. One of our key aims is to develop diagnostics that meet the REASSURED criteria and therefore the diagnostic landscape is always in our mind when developing new technologies.
Selected Research Highlights
Taking Connected Mobile-Health Diagnostics Of Infectious Diseases To The Field
Wood, C.S., & Thomas, M.R., Budd, J., Mashamba-Thompson, T.P., Herbst, K., Pillay, D., Peeling, R.W., Johnson, A.M., McKendry, R.A., and Stevens, M.M., Nature, 566(7745): 467, 2019
As part of a team comprising ICL, UCL, LSHTM, AHRI, UKZN and the KI, we offered a perspective on the potential of mobile-connected diagnostics in the field, and the challenges they face. Mobile health, or ‘mHealth’, is the application of mobile devices, their components and related technologies to healthcare. It is already improving patients’ access to treatment and advice. Now, in combination with internet-connected diagnostic devices, it offers novel ways to diagnose, track and control infectious diseases and to improve the efficiency of the health system. Here we examine the promise of these technologies and discuss the challenges in realizing their potential to increase patients’ access to testing, aid in their treatment and improve the capability of public health authorities to monitor outbreaks, implement response strategies and assess the impact of interventions across the world.
Platinum Nanocatalyst Amplification: Redefining The Gold Standard For Lateral Flow Immunoassays With Ultrabroad Dynamic Range
Loynachan, C.N. & Thomas, M.R., Gray, E.R., Richards, D.A., Kim, J., Miller, B.S., Brookes, J.C., Agarwal, S., Chudasama, V., McKendry, R.A., Stevens, M.M., ACS nano, 12(1): 279-288, 2017
As part of a team from ICL and UCL, a collaboration brought about through the i-sense EPSRC IRC, we developed a highly sensitive lateral flow technology for the detection of HIV. Paper-based lateral flow immunoassays (LFIAs) are one of the most widely used point-of-care (PoC) devices; however, their application in early disease diagnostics is often limited due to insufficient sensitivity for the requisite sample sizes and the short time frames of PoC testing. To address this, we developed a serum-stable, nanoparticle catalyst-labeled LFIA with a sensitivity surpassing that of both current commercial and published sensitivities for paper-based detection of p24, one of the earliest and most conserved biomarkers of HIV. We report the synthesis and characterization of porous platinum core–shell nanocatalysts (PtNCs), which show high catalytic activity when exposed to complex human blood serum samples. We explored the application of antibody-functionalized PtNCs with strategically and orthogonally modified nanobodies with high affinity and specificity toward p24 and established the key larger nanoparticle size regimes needed for efficient amplification and performance in LFIA. Harnessing the catalytic amplification of PtNCs enabled naked-eye detection of p24 spiked into sera in the low femtomolar range (ca. 0.8 pg per mL) and the detection of acute-phase HIV in clinical human plasma samples in under 20 min. This provides a versatile absorbance-based and rapid LFIA with sensitivity capable of significantly reducing the HIV acute phase detection window. This diagnostic may be readily adapted for detection of other biomolecules as an ultrasensitive screening tool for infectious and noncommunicable diseases and can be capitalized upon in PoC settings for early disease detection.