Optimization of paper-based substrates for surface enhanced raman spectroscopic biosensor development

Advancements in the field of analytical chemistry have greatly expanded the development of biosensors for the detection of a wide array of diseases. This study aims to optimize an affordable paper-based nanocomposite biosensor that utilizes surface-enhanced Raman spectroscopy (SERS). Specifically, it investigates the preparation parameters for a paper-based SERS substrate, including nanoparticle administration and drying procedures. A particular focus of this work is to assess how the wax-defined paper channels can effectively enhance SERS intensity. The results revealed that while the wax-printed wells can define the nanoparticle administration for SERS detection, wax backing may reduce the sensitivity of SERS by preventing two-directional solution drying, promoting a non-uniform distribution of nanoparticles on paper substrates. The limit of detection in terms of the number of nanoparticles within the paper-based SERS platform was determined, showing a limit of detection of 0.02% of a theoretical monolayer of gold nanoparticles. These findings, along with preliminary on-going work, suggest that this platform can be expanded with the use of click chemistry for the development of highly sensitive paper-based microfluidic SERS biosensors for the detection of biomarkers in various diseases, such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Automated UAS Aeromagnetic Surveys to Detect MBRL Unexploded Ordnance

Unguided Multiple Barrel Rocket Launcher (MBRL) systems are limited-accuracy, high-impact artillery systems meant to deliver barrages of explosive warheads across a wide area of attack. High rates of failure of MBRL rockets on impact and their wide area of ballistic dispersion result in a long-term unexploded ordnance (UXO) concern across large areas where these systems have been deployed. We field tested a newly-developed UAV (unmanned aerial vehicle)-based aeromagnetic platform to remotely detect and identify unexploded 122 mm rockets of the widely-used BM-21 MBRL. We developed an algorithm that allows near real-time analysis, mapping, and interpretations of magnetic datasets in the field and, as a result, rapid identification of anomalies associated with both surfaced and buried MBRL items of UXO. We tested a number of sensor configurations and calibrated the system for optimal signal-to-noise data acquisition over varying site types and in varying environmental conditions. The use of automated surveying allowed us to significantly constrain the search area for UXO removal or in-place destruction. The results of our field trials conclusively demonstrated that implementation of this geophysical system significantly reduces labor and time costs associated with technical assessment of UXO-contaminated sites in post-conflict regions

A Cost-Efficient Method for Detecting Unexploded 122mm 9M22U Rockets Using Remote Sensing

Unexploded ordnances (UXOs) are any subsurface weapon that pose the threat of detonation. UXOs pose one of the greatest humanitarian concerns of today, as they contaminate land in countries across the globe and lead to thousands of deaths each year. Our research focuses specifically on the BM-21 Grad, a Soviet multiple rocket launcher that fires 122mm rockets with a failure rate of over 4%. This means that the rockets often do not detonate immediately as intended, but become UXOs lodged underground. We studied the use of magnetometry, specifically the UMT MFAM MagPike remote sensor to detect these rockets. We processed data collected from Chernihiv, Ukraine to conclude that BM-21 Grad 122mm rockets do give off magnetic fields that are detectable using magnetometry, and distance above ground level plays a key role in data clarity