Towards commercialising a hybrid nanosensor for screening dispersed nanoparticles and heavy metal ions in natural waters

The problem:

The use of engineered nanoparticles (NP) in cosmetics, pharmaceuticals, sensors and many other commercial applications has been growing exponentially over the past decade. Because of their increasing application many NP are discharged to the watercourse both by industrial companies and through domestic use. The technology for monitoring the environmental impact of these materials, particularly in aquatic systems, is not well developed. It is not only sufficient to be able to determine the NP in water but also it is crucial to have some understanding of their toxicity or biological activity. At the same time, a high throughput screener is urgently required to report on the biomembrane activity (ability to bind to/adsorb on/penetrate biological membranes) of different NP and/or products containing NP dispersed in water. A screening system for NP is therefore required which reports routinely on the level of biologically active NP in raw, waste and drinking waters. At the same time the presence of heavy metal ions in water is always a concern due to their implicit toxicity. These heavy metal ions can be derived from industrial and/or domestic use and in spite of the tremendous advances in the analysis of heavy metal ions in water in the past 50 years, there is currently no routine heavy metal ion screener available for natural and potable waters. A combined NP and heavy metal ion screener therefore would have immediate application in any organisation concerned about the quality of water which comes into contact with human activity.

Addressing the problem:

The proposed technology offers a device which has a dual capability as follows: (1) To screen waters for NP which are biomembrane active and hence are putatively toxic and, (2) To detect toxic heavy metal ions (Cu2+, Pb2+, Cd2+ and Zn2+) in water. The system can also be used to test samples of NP or products containing NP dispersed in water for biomembrane activity. The screening for NP in water is rapid, on-line and high throughput and takes 10 minutes to test each sample. Similarly heavy metal ions in the water can be measured together simultaneously and quantitatively. The NP screener works by looking at the interaction of NP with a phospholipid layer coated on a chip based Pt/Hg microelectrode in a flow cell. This is a development of a previous technology which uses the same device to screen waters for biomembrane active compounds. The heavy metal ions are determined using anodic stripping voltammetry which is a well established analytical technique. The development of the chip-based Pt/Hg electrode in flow cell with flow injection techniques enables both techniques to be used in a high throughput configuration. The switchover from one technique to the other can be readily software controlled.

Benefits which end-users will derive by adopting it:

(1) Screening waters for the presence of biomembrane active NP
(2) Screening products containing NP dispersed in water for biomembrane activity
(3) Screening commercially produced NP dispersed in water for biomembrane activity
(4) Detecting, identifying and quantitatively measuring toxic heavy metal ions in water

The hybrid nanosensor will be of direct benefit to the following:-

(a) Water industry for screening metal/metal oxide nanoparticles (NP) and heavy metal ions in drinking waters and river waters. One of the major applications would be to introduce this technology as a routine test for the presence of these materials in drinking waters at various stages of purification. This will become increasingly important with the use of nanosized materials in water treatment.
(b) Marine agencies to screen NP and heavy metal ions in seawater and assess their putative toxicity. NERC through Plymouth Marine Laboratory funded the science underlying this technology development 1985-2001.
(c) Security and defence to detect presence of toxic NP and heavy metal ions in urban atmospheres and drinking waters. This is a key growth area in the post 9/11 world, although this market has chiefly been driven by US companies.
(d) Pharmaceutical companies for screening biomembrane activity of new bionanomaterials. Pharmaceutical companies normally use cell culture procedures to assay biocompatibility. The proposed current technology has shown proof of principle to measure membrane activity of bionanomaterials e.g peptide bionanomaterials far more rapidly and cheaply than the "conventional" methods.
(e) Biomaterials fabrication to test the biomembrane compatibility of newly fabricated materials especially at the nanometer dimension. NERC have already "start-up" funded the proposer using the older technology to look at the biological activity of engineered nanoparticles (NE/F011830/1).
(f) Consumer products: Unilever and Proctor and Gamble (P & G) would have an interest. Using a sensor like the one proposed would help them not only design better products, but would help them to better understand the chemistry of their activities in-situ and give the public greater confidence in their products.
(g) Health care: The proposed sensor would offer a rapid means of screening preparations intended for applications in health care.

By combining two technologies (NP and heavy metal ions) into one device, the marketing potential of either technology will be greatly enhanced in its appeal to an end user. The project through its various objectives will take the device to the point of (a) licensing to an end user who is prepared to use their resources to commercialise the device, (b) selling the product as a stand-alone item or (c) operating a fees for service consultancy using the technology.

The project will improve the prospect of commercialisation and increase the value of the technology by:-

(a) taking the device from a lab based system to one which can be used in the field with all the technical modifications implemented therein.
(b) carrying out a full performance evaluation of the system to improve its credibility rating.
(c) integrating the very novel NP screening technology with a heavy metal ion detection system founded on well established science (as a continuation of the NERC Pathfinder Funded programme). In this way the risk factor of the technology as perceived by the potential client would be decreased.
(d) focusing the technical and coupled commercial development on licensing the technology to a partner in the Water Industry or a closely associated grouping.
(e) Packaging the system so that it can be sold as a stand-alone product.