Diaminocyclohexane-Functionalized/Thioglycolic Acid-Modified Gold Nanoparticle-Based Colorimetric Sensing of Trinitrotoluene and Tetryl

Abstract

Detection of explosive residues in soil and postblast debris is an important issue in sensor design for environmental and criminological purposes. An easy-to-use and low-cost gold nanoparticle (AuNP)-based colorimetric sensor was developed for the determination of nitroaromatic explosives, i.e., trinitrotoluene (TNT) and tetryl, capable of analyte detection at picomolar (pM) levels. The sensor nanoparticles were synthesized by functionalizing the negatively charged thioglycolic acid (TGA)-modified AuNPs with positively charged (±)-trans-1,2-diaminocyclohexane (DACH) at a carefully calculated pH. The working principle of the sensor is charge-transfer (CT) interaction between the electron-rich free amino (−NH 2 ) group of DACH and the electron-deficient −NO 2 groups of TNT/tetryl, added to possible nanoparticle agglomerization via electrostatic interaction of TNT-Meisenheimer anions with more than one cationic DACH-modified AuNP. The limit of detection (LOD) and limit of quantification (LOQ) of the sensor were 1.76 pM and 5.87 pM for TNT and 1.74 pM and 5.80 pM for tetryl, respectively. TNT, tetryl, and tetrytol, extracted from a nitroaromatic explosive-contaminated soil sample, were determined with the proposed sensor, yielding good recoveries. The sensor could be selectively applied to various mixtures of TNT with common energetic materials such as RDX, HMX, and PETN. Additionally, common soil ions (Cl − , NO 3 − , SO 4 2− , K + , Mg 2+ , Ca 2+ , Cu 2+ , Fe 2+ , Fe 3+ , and Al 3+ ) as well as detergents, sugar, sweeteners, acetylsalicylic acid (aspirin), caffeine, and paracetamol-based painkiller drugs, which may be used as camouflage materials for explosives, either had no adverse effects or removable interferences on the detection method. The developed method was statistically validated against a GC−MS literature method.

Carbon Dots for Forensic Applications: A Critical Review

“…To that end, quantum dots [65,66], plasmonic nanoparticles [67][68][69][70], carbon nanotubes [71] and graphene [72] have been widely explored for the development of affinity-based nanoprobes to detect common narcotics [65,66], anabolic steroids [71], drugs with abuse potential [69], explosives [67,72] and pathogens that can potentially be linked to bioterrorism [68], as well as to determine time since death [70]. Moreover, wearable biosensors can monitor continuously and in real time adverse lifestyle habits associated with criminal behaviour, such as the excessive use of alcohol [73].…”

AuNPs as an important inorganic nanoparticle applied in drug carrier systems

“…In addition to sizes and shapes of AuNPs, many studies have shown that the surface charge of AuNPs played a critical role in modulating cellular uptake [134]. The surface charge of AuNPs includes positively charges [135], negatively charges [136] and neutral charges [137]. Positively charged surfaces preferentially increase cellular uptake due to the negatively charged surface of the cells.…”

A luminescent Zn-MOF for the detection of explosives and development of fingerprints

“…The excessive use of nitro compounds to fulfill human requirements leads to an increase in the concentration of aforesaid pollutants in the atmosphere and causes different forms of environmental pollution including water pollution. 5 Also, the recent literature supported the contamination of groundwater and other water bodies by explosive materials like TNT 5–9 and their derivatives. The contamination of water systems by these explosive materials makes them highly toxic and that's why the US Environmental Protection Agency (EPA) has set a permissible limit of 2 ppb in drinking water.…”

“…Therefore, we need very sensitive, selective and cost-effective methods for the detection of nitro compounds at low concentrations. Various techniques are available in the literature for the detection of explosive compounds such as surface plasmon resonance; RDX, 12 colorimetric; TNT, Tetryl, 13 electrochemical; 14 liquid chromatography-mass spectrometry, 15 fluorometry (TNT) 16 and surface-enhanced Raman scattering; (TNT), 17 high-performance liquid chromatography; (TNT, RDX, PETN & HMX), 18,19 etc. Among these reported methods, fluorescence-based detection of explosive compounds is generally preferred due to its quick response, cost-effectiveness, short duration, high selectivity, and easy operation.…”

“…For the development of fluorescent sensors, a variety of probes have been constructed using nanoparticles, 25–30 small molecules, 3,31 polymeric materials, 10 and porous materials including covalent organic frameworks (COFs) and metal–organic frameworks (MOFs) 1,8,32–36 for the detection of explosive materials. Specifically, luminescent MOFs generally have been anticipated for the sensing of explosive materials due to the high porosity, 37–40 large surface area, 41,42 and adjustable functionality within the framework, 21 which makes MOFs suitable candidates for sensing applications.…”