Superfund Research Program
Lipid Enhanced Nano-Sensors (LENS) for lead and mercury detection in water
Project Leader: Steven Lenhert
Grant Number: R41ES028643
Funding Period: Phase I: September 2017 - May 2019
Lead, copper, and mercury are very common in the environment and the public are exposed to these trace toxic metals through different routes. The lead contamination in Flint drinking water is a tragic example where public health, especially children's health, was severely impacted by old infrastructure that contains these toxic metals. Millions of people in the U.S. still live in places with these contaminants, and crises like the Flint water crisis could occur. An unmet need exists for technologies for personal exposure assessments at the point of contact.
Current testing for metal ions is mostly performed in formal reference laboratories. Commercially available home-based water filter systems do not measure metal ions at an affordable price. Zansors is determining the feasibility of using lipid enhanced nanosensor (LENS) arrays for smart-phone based detection of lead (Pb2+) and mercury (Hg2+) in drinking water at concentrations above FDA allowable levels.
LENS arrays are composed of fluid lipid multilayer diffraction gratings on surfaces. The fluid nature of these arrays has two advantages (1) reagents can be included within the grating volume, and (2) changes in the grating nanostructure upon analyte binding results in an optical readout signal. The sensors are being adapted for selective detection of lead and mercury in a laboratory setting. This is being done by functionalizing the sensor elements with nucleotide sequences known to bind lead and mercury ions. The sensitivity and selectivity of the individual sensor elements is also being determined. These elements are then being integrated into arrays composed of different lipid formulations using nanointaglio printing. The researchers are further obtaining the selectivity for the analytes at concentrations above FDA allowable levels by using an optical nose approach.
In order to achieve portability and affordability, Zansors is developing a smart-phone attachment that makes use of the light source camera for detection. The attachment will require a sample volume of one drop (i.e. less than 10 microliters). Finally, the LENS arrays are being tested on real-world water samples spiked with the ions of interest.
Zansor's ultimate goal is to produce an affordable general-purpose smart-phone attachment and specific cartridges for detecting analytes of interest to the consumer. They are working to demonstrate the technical feasibility of using LENS arrays for detection of lead and mercury in drinking water. As the LENS array technology is potentially scalable, there is potential for multiplexed detection of thousands of analytes from a single drop.