Final Report: Handheld Microfluidic Device for Cyanobacteria Toxin Detection and Monitoring

EPA Contract Number: EPD13014
Title: Handheld Microfluidic Device for Cyanobacteria Toxin Detection and Monitoring
Investigators: Jiao, Hong
Small Business: HJ Science & Technology Inc.
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: May 15, 2013 through November 14, 2013
Project Amount: $79,957
RFA: Small Business Innovation Research (SBIR) - Phase I (2013) RFA Text |  Recipients Lists
Research Category: SBIR - Water , Small Business Innovation Research (SBIR)

Description:

In this SBIR Phase I project, HJ Science & Technology proposes to demonstrate the feasibility of a microfluidic automation technology capable of rapid and real time detection and identification of a variety of toxins in drinking water, particularly microcystins and other toxins produced by cyanobacteria. During blooms, these toxins in freshwater become concentrated enough to be a serious concern for human health, causing damage to the liver and nerve axons. EPA currently recommends a limit of 1 ppb for microcystins in drinking water. The proposed technology is inexpensive, easy to use and has a portable platform. Compared with laboratory-based methods, the onsite portable detection platform offers advantages such as reduction in time and cost, as well as real-time data for better and more timely decisionmaking. HJ Science & Technology’s portable device is designed to address several shortcomings of current portable technologies. Specifically, it is designed to perform rapid detections of cyanotoxins with sensitivity and specificity that are currently only achievable with laboratory-based instruments. The company's technical approach is to transfer commercial enzyme-linked immunosorbent assay (ELISA) protocol to its microfluidic automation format to achieve sub-ppb levels of detection sensitivities for a variety of chemicals and toxins in low concentrations in water to meet the stringent regulatory requirement. In Phase I, HJ Science & Technology focuses on microcystins because they are one of the most common cyanobacteria toxins in the Great Lakes and other sources of drinking water in the United States. The company’s approach is to adapt the commercial microcystin ELISA protocol to its microfluidic automation platform.

Summary/Accomplishments (Outputs/Outcomes):

In this successful SBIR Phase I effort, HJ Science & Technology has established the technical feasibility of a novel microfluidic device capable of performing rapid and real-time automated direct competitive ELISA for cyanobacteria toxins in water samples. The heart of the company’s innovation is a disposable microfluidic cartridge, consisting of novel microvalves and micropumps, that can precisely control the delivery and the flow of sample and reagents, thereby being capable of complete end-to-end assay automation. HJ Science & Technology has performed the automated ELISA by selecting and sequentially pumping reagents, including the capture antibody, blocking reagent, sample, HRP conjugate, and substrate through the microchannel network. Automated intermediate washing steps effectively removed unbound species, resulting in a high signal-to-noise ratio. In the Phase I feasibility study:
  • HJ Science & Technology has successfully adapted a commercial direct competitive ELISA protocol for microcystin to the company’s miniaturized microfluidic automation format;
  • the microfluidic automation platform has a detection limit of 0.16 ppb (regulatory limit is 1ppb); and
  • the results are comparable to the commercial manually prepared ELISA kit.
HJ Science & Technology has achieved its Phase I goal by accomplishing all four of the proposed technical objectives:
  1. Successfully designed, fabricated, and characterized several microfluidic devices capable of performing automated immunoassay for microcystin.
  2. Successfully performed ELISA with its microfluidic automation format and achieved the desired qualitative results by visually inspecting the color change of the detection substrate.
  3. Designed and built the necessary optical instrumentation components, and successfully performed automated ELISA with excellent quantitative results compared with manually prepared ELISA with commercial 96-well microplates.
  4. Successfully designed, fabricated and tested a Phase II prototype microfluidic cartridge.

Conclusions:

In this SBIR Phase I effort, HJ Science & Technology has achieved all of the stated technical objectives. By establishing the technical feasibility of the automated competitive ELISA capability, the Phase I results clearly show that the company’s microfluidic automation technology can be used to develop a portable field deployable instrument for detection and analysis of microcystin and other cyanobacteria toxins. Due to the success of this Phase I research, HJ Science & Technology is pursuing SBIR Phase II funding to further develop a portable prototype capable of performing on-site detections of a variety of cyanobacteria toxins.

Compared to traditional analytical methods, the proposed microfluidic technology provides capability for automation, portability, fast and real-time analysis. It therefore has broader commercial applications in addition to cyanobacteria toxins to include other common environmental pollutants present in drinking water and soil. The key target commercial customers include water resource managers, public health officials and aquaculture facilities.

Supplemental Keywords:

cyanobacteria toxins, drinking water, electrochemical membrane sensors, fluorescence detection, ELISA

Progress and Final Reports:

Original Abstract

SBIR Phase II:

Handheld microfluidic device for cyanobacteria toxin detection and monitoring