A low-cost, portable optical explosive-vapour sensor

Abstract

Highlights Arduino-based optical instrument for explosives detection designed and prototyped  Few-ppb detection of 2,4-DNT achieved under laboratory conditions with simple photodiode circuitry and off-the-shelf microprocessor  Simulated buried landmines successfully detected Abstract Humanitarian demining requires a broad range of methodologies and instrumentation for reliable identification of landmines, antipersonnel mines, and other explosive remnants of war (ERWs). Optical sensing methods are ideal for this purpose due to advantages in sensitivity, time-of-response and small form factor. In this work we present a portable photoluminescence-based sensor for nitroaromatic vapours based on the conjugated polymer Super Yellow integrated into an instrument 2 comprising an excitation LED, photodiode, Arduino microprocessor and pumping mechanics for vapour delivery. The instrument was shown to be sensitive to few-ppb concentrations of explosive vapours under laboratory conditions, and responds to simulated buried landmine vapour. The results indicate that a lightweight, easy-to-operate, low-cost and highly-sensitive optical sensor can be readily constructed for landmine and ERW detection in the field, with potential to aid worldwide efforts in landmine mitigation.

Adaptive and sensitive fibre-optic fluorimetric transducer for air- and water-borne analytes

“…4. Nevertheless, our LoD compares favourably to LoD of 30 ppb reported in [15] for detection of DNT with similar PPV polymer and a conventional spectrometer.…”

“…This indicates better solvation of analyte in water vs. air. We found LoD of 10.9 ppb in air and 56 ppb in water which are ~ 2.7 times below previously reported LoDs for DNT sensing with PPV derivatives [15,16]. We consider our study of the MDMO-PPV / DNT system as a successful test of our transducer design and recommend its wider use for other sensitiser / analyte systems.…”

“…Limit-of-detection (LoD) for airborne DNT is 10.9 ppb and 55.7 ppb for waterborne DNT. Our transducer compares favourably to alternative systems using PPV fluorophores for the detection of nitroaromatic vapours [15] and solutions [16,2], and we propose to adopt it more widely for fluorimetric sensing.…”

Preconcentration techniques for trace explosive sensing

“…2007; Toal and Trogler, 2006;Wang et al, 2011b;Yang and Swager, 1998). Instrumentation based on exploiting these materials has been developed for humanitarian demining applications (Gillanders, 2017;Wang et al, 2011a) in recent years. The commercial organic polymer shown in Figure 1 (a) from Merck, Super Yellow, exhibits high sensitivity to nitroaromatic compounds including 2,4-DNT, a common component in landmine manufacture and a degradation product of TNT.…”

“…To confirm the preconcentration action in a simulated minefield environment, the Aflas polka-dotted onto Whatman filter paper discs were placed over a simulated landmine containing 1g of DNT in a metal container buried in soil at a depth of 2 cm as described in (Gillanders, 2017). The relative humidity around the simulated landmine was increased to 70-80% before sampling with a water mist as this has been shown to maximise the amount of explosive vapour emitted by a landmine (Bach and Mclean, 2003).…”