Titanium dioxide nanoparticles-based colorimetric sensors for determination of hydrogen peroxide and triacetone triperoxide (TATP).

Due to its relatively simple preparation and readily available precursors, determination of triacetone triperoxide (TATP) by portable devices has become important. In this work, two different titanium dioxide nanoparticles (TiO2NPs)-based colorimetric sensors based on complex formation on the solid surface were developed for determination of H2O2 and TATP. The first sensor, (3-aminopropyl)triethoxysilane (APTES) modified-TiO2NPs-based paper sensor (APTES@TiO2NPs), exploits peroxo-titanate binary complex formation between APTES@TiO2NPs and H2O2 on chromatographic paper. The second sensor, 4-(2-pyridylazo)-resorcinol-modified-TiO2NPs-based solid sensor (PAR@TiO2NPs), relies on the formation of a ternary complex between Ti(IV), PAR and H2O2. The developed sensors were also applied to TATP determination after acidic hydrolysis of samples to H2O2. The limits of detection (LODs) of APTES@TiO2NPs-based paper sensor were 3.14 × 10-4 and 5.13 × 10-4 mol L-1 for H2O2 and TATP, respectively, whereas the LODs of PAR@TiO2NPs solid sensor were 6.06 × 10-7 and 3.54 × 10-7 mol L-1 for H2O2 and TATP, respectively. Possible interferences of common soil ions, passenger belongings used as camouflage materials during public transport (e.g., detergent, sweetener, acetylsalicylic acid and paracetamol-caffeine based analgesic drugs) and of other explosives were examined. The developed methods were statistically validated using t- and F- tests against the titanyl sulfate (TiOSO4) colorimetric literature method.