Access to routine medical services, let alone high-tech diagnostic and treatment equipment, is nearly impossible in many developing nations. Many countries are battling endemic diseases that are difficult to control. “Such countries are considered to have low living standards, weak industry, and a low human development index… a measure of poverty, literacy, education and life expectancy.”¹The U.N. Millennium Development Goals, which enumerate global initiatives to improve the global quality of life, include “halve the proportion of people without sustainable access to safe water and sanitation by 2015.”² Ongoing conflicts, a widely scattered population, and a weak infrastructure often combine to make the delivery of essential healthcare extremely challenging.

Localized surface plasmon resonance (LSPR) or point of care technology (PoCT) has the potential to truly make a difference in how diseases are diagnosed and contaminants identified.

In rural areas, traveling to visit a doctor is simply out of the question. Disease can sometimes infect an entire village, and it will take days before word reaches healthcare professionals. Doctors and medical workers need to be equipped with tools that can easily travel with them to visit patients and provide answers in the field that can then be verified using more traditional and proven methods back in the lab.

However, sending test samples back to the lab and waiting for results isn’t always a feasible option when in a remote area. With smartphone based SPR technology, scientists will only need a phone, a disposable SPR chip and a small scaffold that is totally portable.

Early models of LSPR systems are capable of detecting the presence of viral material, bacteria, antibodies and other biological materials with impressive accuracy. Zhang, et al., predict: “With advances in micro-manufacture, sensor technology, and miniaturized electronics, biosensor and bioelectronic devices on smartphone can be used to perform biochemical detections as … electronic tag readout in future.”³ Other applications include food safety monitoring, “as these handheld devices can be used to detect the E. coli bacterium in food and beverages.” The recent funding for US FDA’s implementation of the Food Safety Modernization Act could speed the development of handheld food safety monitoring devices. The detection mechanisms will be developed based on and understanding of the fundamental biology utilizing lab based SPR technology. Once fully characterized, the diagnostic consumables and test conditions required at PoC can be developed.

High performance cameras that are ubiquitous in today’s smartphones help produce insightful results. The smartphone display is capable of producing enough light to trigger the necessary reactions and the camera aids in optical detection and record keeping without requiring any additional equipment. Ultimately, the result is a surprisingly sensitive, lightweight and portable SPR diagnostic machine.

Smartphone-based devices can also be used to detect certain environmental toxins or pollutants; including lead. Those familiar with the recent state of emergency in Flint, Michigan will realize that the technology is needed in both industrialized and developing nations. In 2014, Flint drinking water exceeded the TTHM limit specified by the “Stage 2 Disinfectants and Disinfection Byproducts Rule.”4 Currently, the municipal water supply contains unsafe levels of lead.

As Professor Brian T. Cunningham of the Nano Sensors Group notes, “Such a system, deployed widely, would be capable of rapidly monitoring for the presence of environmental contaminants over large areas, or tracking the development of a medical condition throughout a large population."5

“… surface plasmon resonance (SPR) based and photonic crystal (PC) optical biosensors are capable of detecting broad classes of biological analytes through their intrinsic dielectric permittivity. Each approach has been successfully implemented in the form of large laboratory instruments, and miniaturized (shoebox-sized) systems.”

For doctors fighting diseases in remote areas where terrain and weather present their own challenges, the prospect of being able to take SPR diagnostic equipment into the field presents an exciting evolution in medicine. The recent funding for US FDA’s implementation of the Food Safety Modernization Act could speed the development of handheld food safety monitoring devices.

While still in the early stages, these PoC devices are an exciting extension of SPR technology that could extend its utility from the discovery phase through to PoC diagnostics.



Hammond, J., Bhalla, N., Rafiee, S., & Estrela, P. (2014). Localized Surface Plasmon Resonance as a Biosensing Platform for Developing Countries. Biosensors, 4(2), 172-188.
Hammond, J., Bhalla, N., Rafiee, S., & Estrela, P. (2014). Localized Surface Plasmon Resonance as a Biosensing Platform for Developing Countries. Biosensors, 4(2), 172-188.
Zhang, D., & Liu, Q. (2016). Biosensors and bioelectronics on smartphone for portable biochemical detection. Biosensors and Bioelectronics, 75, 273-284.
http://www.waterandhealth.org/tthm-drinking-water-flint-michigan-story-lesson/
Smartphone Biosensors: Lab-in-a-Pocket Diagnostics by Professor Brian T. Cunningham http://bit.ly/1mobgoY