Author
KOH, CHUNG-YAN - Sandia National Laboratory | |
SCHAFF, ULRICH - Sandia National Laboratory | |
PICCINI, M - Sandia National Laboratory | |
Stanker, Larry | |
Cheng, Luisa | |
RAVICHANDRAN, EASWARRAN - University Of Massachusetts | |
SING, BAL-RAM - University Of Massachusetts | |
SOMMER, GREG - Sandia National Laboratory | |
SINGH, ANUP - Sandia National Laboratory |
Submitted to: Analytical Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/17/2014 Publication Date: 12/18/2014 Citation: Koh, C., Schaff, U.Y., Piccini, M., Stanker, L.H., Cheng, L.W., Ravichandran, E., Sing, B., Sommer, G.J., Singh, A.K. 2014. Centrifugal microfluidic platform for ultrasensitive detection of Botulinum Toxin. Analytical Chemistry. 87(2):922-928. DOI: 10.1021/ac504054u. Interpretive Summary: Botulism is a serious, often fatal neuroparalytic disease in humans and animals caused by a protein toxin (botulinum toxin, BoNT) produced by the bacterium Clostridium botulinum. BoNT is considered the most toxic biological toxin known. Because of its high toxicity, the need for a long recovery period requiring extensive treatment, and the ease of producing BoNT,it is considered a class A bioterrorism agent. These same properties make the toxin difficult to study. In this report a rapid, ultra-sensitive assay for BoNT using a novel biosensor that purifies and measures the toxin in a single device. The availability of this assay will enhance our ability to monitor for toxin in food and provide enhanced public safety. Technical Abstract: Botulinum neurotoxin – a global public health threat and category A bioterrorism agent - is the most toxic substance known and one of the most challenging toxins to detect due to its lethality at extremely low concentrations. Hence the live-mouse bioassay because of its superior sensitivity, remains the gold-standard despite its exceedingly high cost, need for specialized facilities and expertise, and time-consuming protocols. We have developed a simple, sample-to-answer microfluidic platform that vastly outperforms the antiquated live-mouse bioassay for botulinum neurotoxin serotype A (BoNT/A). The SpinDxTM platform employs a sedimentation-based centrifugal immunoassay and requires no sample preparation for clinical, food, and environmental samples. A blind, head-to-head comparison study of SpinDxTM versus the live-mouse bioassay demonstrates 100-fold improvement in sensitivity (limit of detection = 0.09 pg/mL), while achieving total sample-to-answer time of <30 minutes with 2-uL required volume of unprocessed sample. We further demonstrate BoNT/A quantification without any loss of sensitivity directly from the sera of intravenously-, orally-, and intranasally-intoxicated mice, as well as from untreated food samples including canned meat, carrot juice, peanut butter, and salad dressing with no additional sample preparation. |