Multi-channeled single chain variable fragment (scFv) based microfluidic device for explosives detection

Abstract

The development of explosives detection technologies has increased significantly over the years as environmental and national security agencies implement tighter pollution control measures and methods for improving homeland security. 2, 4, 6-Trinitrotoluene (TNT), known primarily as a component in munitions, has been targeted for both its toxicity and carcinogenic properties that if present at high concentrations can be a detriment to both humans, marine and plant ecosystems. Enabling end users with environmental detection and monitoring systems capable of providing real-time, qualitative and quantitative chemical analysis of these toxic compounds would be extremely beneficial. Reported herein is the development of a multi-channeled microfluidic device immobilized with single chain fragment variable (scFv) recombinant proteins specific for the explosive, TNT. Fluorescence displacement immunoassays performed under constant flow demonstrated trace level sensitivity and specificity for TNT. The utility of three multi-channeled devices immobilized with either (1) scFv recombinant protein, (2) biotinylated-scFv (bt-scFv) and (3) monoclonal anti-TNT (whole IgG molecule) were investigated and compared. Fluorescence dose response curves, crossreactivity measurements and limits of detection (LOD) for TNT were determined. Fluorescence displacement immunoassays for TNT in natural seawater demonstrated detection limits at sub-parts-per-billion levels (0.5 ppb) utilizing the microfluidic device with immobilized bt-scFv.

Continuous microfluidic assortment of interactive ligands (CMAIL)

“…Microfluidic technology confers advantages, including the precisely controlled fluidic environment and amiability to be automated, and has been developed and applied for molecular separations131415 and detections161718. For example, it has been shown that microfluidic devices can provide a much more accurate and automatic handling of fluids in the biopanning procedure192021222324.…”

Impact of TNT explosive and its degradation products on the environment

“…Određivanje u specijalnim laboratorijama je skupo i nije fleksibilno. Osim toga, uzorkovanje može prouzrokovati greške [1,3,10,13,15-18, [25][26][27].…”

“…pak, neophodna su dalja istraživanja, naročito u oblastima masenog bilansa, smanjenja troškova i potpune mineralizacije [21]. Novije metode remedijacije su fluorescencija [6,10,27], elektrohemijske metode [25,27], fitoremedijacija [5,6,8,9,12], fotolitička transformacija [2,20], super kritična ekstrakcija tečnosti ugljendioksidom (SC-CO 2 ) [17], UC luminescencija [13,26,27], bioluminescencija [1,3], bioremedijacija [1, 4,5,7,8,11,18,[21][22][23][28][29][30], Fenton proces [2,5]. Svaka od ovih tehnologija poseduje niz prednosti, ali i mana kao što su previsoki troškovi, komplikovana aparatura, i zahtev za tehničko obučenim osobljem za efikasno funkcionisanje [22,26,27].…”

A High Aspect Ratio Bifurcated 128-Microchannel Microfluidic Device for Environmental Monitoring of Explosives

“…Microfluidic devices have proven their effectiveness in many disciplines of scientific research; proteomic analysis [ 7 ], macro-algae bloom investigations [ 8 ], biochemical mechanisms in 3D cell-based systems [ 9 ], paper-based microfluidic devices for biomarkers for disease and point of care diagnostics [ 1 ] and explosives detection [ 10 , 11 ]. Although traditional benchtop explosives detection systems and devices [ 12 ], and Singh’s method [ 13 ] continue to remain as the gold standard, microfluidic devices can in the near future provide a miniaturized, versatile, field portable platform capable of achieving the highest level of sensitivity.…”

“…Prior research within our group has focused on the development of technologies for the detection of explosives that provide; (1) a superior level of detection sensitivity; (2) flexibility to be miniaturized; (3) durability; (4) low cost to manufacture; and (5) high sample throughput. Investigations were conducted with a PMMA-modified 39-multichanneled microfluidic device for the detection of explosives [ 10 , 11 , 17 , 18 ] with targeted intentions for field applications. This report investigates a new design, fabrication, theoretical analysis and sensor integration of a 128-microchannel microfluidic device for explosives detection (specifically TNT) that offers the potential for enhanced sensor performance.…”