Lee Y.-G.,Sungkyunkwan University |
Han J.,Siloam Biosciences, Inc. |
Kwon S.,Mine Reclamation Corporation |
Kang S.,Kyung Hee University |
Jang A.,Sungkyunkwan University
Chemosphere | Year: 2016
Atomic absorption spectrometry and inductively coupled plasma-mass spectrometry are widely used for determination of heavy metals due to their low detection limits. However, they are not applicable to on-site measurements of heavy metals as bulky equipment, and highly skilled laboratory staffs are needed as well. In this study, a novel analytical method using a rotary disc voltammetric (RDV) sensor has been successfully designed, fabricated and characterized for semi-continuous and on-site measurements of trace levels of Pb(II) in non-deoxygenating solutions. The square wave anodic stripping voltammetry was used to improve the sensitivity of the Pb(II) detection level with less than 10nM (2μgL-1). The RDV sensor has 24-sensing holes to measure concentrations of Pb(II) semi-continuously at sampling sites. Each sensing hole consists of a silver working electrode, an integrated silver counter, and a quasi-reference electrode, which requires only a small amount of samples (<30μL) for measurement of Pb(II) without disturbing and/or clogging the sensing environment. In addition, the RDV sensor showed a correlation coefficient of 0.998 for the Pb(II) concentration range of 10nM-10μM at the deposition time of 180s and its low detection limit was 6.19nM (1.3μgL-1). These results indicated that the advanced monitoring technique using a RDV sensor might provide environmental engineers with a reliable way for semi-continuous and on-site measurements of Pb(II). © 2015 Elsevier Ltd. Source
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 372.94K | Year: 2008
DESCRIPTION (provided by applicant): The objective of this revised fast-track effort is the development of reliable, high-throughput microfabrication techniques for production of lab-on-a-chip for Point-of-Care Testing (POCT) applications. The proposed fabrication processes will significantly improve the throughput of plastic lab-on-a-chip manufacturing processes while making the process more reliable. The processes developed in this work will allow (a) Siloam to successfully commercialize lab-on-a-chip applications under development and (b) serve as cornerstone of development for the BioMEMS industry by offering fully-automated processes for lab-on-a-chip fabrication. The current plastic lab-on-a-chip production processes include a mix of processes with varying throughput. Low-throughput processes such as drilling, dicing, microfluidic interconnect assembly present significant bottlenecks to the high-throughput desirable of production processes. This effort proposes a systematic development of plastic microfabrication processes that can completely eliminate the low-throughput processes. Furthermore, the newly developed process sequence will allow for a fully-automated process flow which can dramatically enhance the throughput as well as reliability of a production process. During Phase I efforts, research efforts will focus on development of the high-throughput plastic microfabrication processes. A double-side injection molding process is proposed that can enhance the functionality of the injection molding process by allowing for fabrication of (a) through-holes geometries (eliminates drilling), (b) automatic definition of chip size (eliminates dicing), and (c) self-alignment during assembly (increases accuracy and reliability). Also, a novel mechanically-assisted thermoplastic fusion bonding protocol is proposed which can dramatically increase the throughput for the bonding step (few seconds per device). This process relies on a high density array of interlocking pillar-hole structures (fabricated using double-side injection molding) which allows for rapid chip assembly (at room temperature). Following assembly, a batch of assembled chips is simultaneously annealed (at high temperature) which leads to chemical bond formation across the interface. Finally, self-aligning microfluidic interconnects which can be incorporated as a part of the assembly process will be developed. A multi-layer microfluidic device using all of the above processes will be fabricated as a proof-of-concept demonstration vehicle. During Phase II efforts, the merit of the newly developed fabrication processes will be demonstrated by fabrication of lab-on-a-chips for specific BioMEMS applications. The use of the new technology will (a) either improve existing microfluidic devices or; (b) make possible microfluidic devices that were not possible with current fabrication processes. POCT diagnostic tools, using disposable lab-on-a-chips will allow for frequent patient monitoring leading to more informed and clinically relevant decisions from physicians. The manufacturing processes proposed in this work, for microfluidic lab-on-a-chips, are crucial for successful commercialization of this technology.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 997.44K | Year: 2014
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 997.25K | Year: 2011
Recent clinical research has established that this ratio is indicative of the activity of the CYP2A6 enzyme that metabolises nicotine. Nicotine is metabolized to COT and then to 3HC. People with high activity of this enzyme, clear nicotine faster and henceneed more nicotine to maintain the addiction. To-date the 3HC/COT ratio could only be determined by specialized measurement techniques such as Liquid-Chromatography/Mass Spectrometry. Although accurate, these tests are expensive and take 2-5 days to deliver results. Smoking is the leading cause of cancer related deaths, and is attributable cause for almost 400,000 deaths per year in the US> The POCT for nicotine metabolites can help in increasing smoking cessation rates and directly contribute to reduced mortality/healthcare burden.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2010
The goal of this fast-track SBIR project is to develop the first ever, point-if-care test (POCT) to determine the ratio of nicotine metabolites