Innovative Sensor Technologies for Trace Detection of Organic Peroxide Explosives and Industrial Hydroperoxides

Abstract

We report a multi-modal strategy to examine titanium(IV)-based colorimetric thin films for the vapor-phase response of organic peroxide compound such as tert-butyl hydroperoxide (TBHP), cumene hydroperoxide (CHP), triacetone triperoxide (TATP), and hexamethylene triperoxide diamine (HMTD), with observable colorimetric responses corresponding to peroxide vapor exposure in the sub-ppm to ppm equivalency range. These compounds are classified as peroxidebased explosives or industrially relevant hazardous compounds, and their detection at trace levels is critical for forensic, security, and environmental monitoring applications. The study employs a multi-modal detection approach integrating gas chromatography-mass spectrometry (GC-MS), ion mobility spectrometry (IMS), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). GC-MS and IMS were employed for qualitative confirmation and comparative differentiation of peroxide vapors, while FTIR reveals distinct absorption bands indicative of chemical and physical interactions. Colorimetric detection methods are designed based on selective chemical reactions of these compounds, demonstrating visible responses at trace levels. Furthermore, atomic force microscopy (AFM) was utilized to investigate the structural and morphological changes upon exposure to these peroxides, providing nanoscale insight into film morphology before and after exposure. The combination of these comparable techniques demonstrates reproducible and distinguishable responses under controlled laboratory conditions with minimal interference from complex environmental matrices. This multi-modal analytical strategy highlights its potential for forensic applications, environmental monitoring, and counterterrorism efforts, highlighting its potential relevance for laboratory screening and future development of portable peroxide detection systems.