Determination of hydrogen peroxide and triacetone triperoxide (TATP) with a silver nanoparticles-based turn-on colorimetric sensor

- Peroxide explosives were detected with a silver nanoparticles (AgNPs)-based sensor.
- H2O2 oxidized AgNPs to Ag+, which in turn oxidized 3,3′,5,5′-tetramethylbenzidine.
- Turn-on colorimetric sensing at 655 nm was optimized for quantitating H2O2 and TATP.
- Analytical figures of merit were determined, with an LOD of 20 nM for H2O2.
- Sensor was tested for common interferents and validated against reference methods.

Hydrogen peroxide (H2O2) is a synthetic precursor and degradation product of peroxide-based explosives, such as TATP. We developed a colorimetric sensor that is selective, sensitive, cost-efficient and easy-to-use in conventional laboratories for the naked eye detection of hydrogen peroxide and for indirect determination of peroxide-based explosives (which are devoid of chromogenic/fluorogenic functional groups). We were able to partly oxidize zero-valent silver nanoparticles (Ag0NPs) by H2O2 to Ag+ under special conditions, and thus devise an indirect method for trace H2O2 quantification by measuring the absorbance of the blue-colored diimine of TMB (3,3′,5,5′- tetramethylbenzidine) at 655 nm, arising from TMB oxidation with Ag+. TATP was acid-hydrolyzed to H2O2 by an acidic cation-exchanger (Amberlyst-15) for potential field use. The limit of detection (LOD) of the sensor was 20 nM for H2O2 and 0.31 mg L−1 for TATP. Common soil ions did not interfere, and TATP was analyzed in synthetic mixtures of other energetic materials. The responses of detergents, sweeteners, acetylsalicylic acid (aspirin) and paracetamol-based painkiller drugs, used as camouflage material in passenger belongings, were also examined. The developed method was statistically validated against the standard analytical methods of titanium(IV) oxysulfate (TiOSO4) for H2O2 and GC-MS for TATP using t- and F- tests.

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