Ali Yetisen and Professor Christopher R. Lowe have developed a holographic nanosensor that allows sensing divalent metal cations and organic solvents – increasing the possibility of low-cost point-of-care devices for medical diagnostics and environmental monitoring.
The team has developed a new technique that allowed rapid fabrication of holographic nanosensors in two steps, the fastest optical sensor production technique reported up to date.
The study demonstrated quantification of copper and iron ions. For example, copper sensors can be used in the diagnosis of Wilson's disease, an autosomal recessive genetic disorder in which copper accumulates in tissues. Additionally, detection of iron concentrations in bodily fluids can allow the screening of iron deficiency anaemia.
The nanosensor’s principle of operation is based on visible-light Bragg diffraction, which produces a monochromatic colour corresponding to the concentration of a specific molecule in solution. Experimental results showed that the nanosensor was highly sensitive and produced reversible colours in the visible spectrum.
In their study, published in Journal of Materials Chemistry C, they have shown the feasibility of this new sensing platform.
Reprinted with permission from Journal of Materials Chemistry C. Copyright 2014. The Royal Society of Chemistry.
The sensing capacity of the holographic nanosensors was also shown in the quantification of organic solvents such as ethanol, methanol, propan-2-ol, dichloromethane, chloroform and tetrahydrofuran.
These flammable solvents pose health hazards due to their toxicity to the nervous and respiratory system, while also causing damage to liver and kidney. For example, counterfeit alcoholic drinks can contain high concentrations of methanol (a low-cost substitute for ethanol) that cause blindness.
The team is currently building a prototype test suitable for clinical settings and home testing. The clinical trials of the nanosensor will take place in Cambridge’s Addenbrooke’s Hospital.
This work was a multidisciplinary effort bringing together the researchers from our department and the Department of Engineering (Dr. Malik Qasim and Professor Tim Wilkinson).
It is anticipated that the holographic nanosensing platform will lead to many novel applications from biochemical sensing to printable optical devices.