Understanding of mechanistic perspective in sensing of energetic nitro compounds through spectroscopic and electrochemical studies

Abstract

Understanding the probable mechanism of detection plays a significant role in selecting a particular fluorophore for the detection of the complicated and low volatile analyte namely, nitroaromatic and non-aromatic high energy materials (HEMs) in the development of detection devices when compared with the existing techniques. The fluorescence quenching employing conducting polymers-based response of HEMs have attained great significance in recent times. Amongst all conducting polymers, functionalized polyaniline can act as a fluorophore in quenching studies. This report also reveals the importance of studying electrochemical methods associated with the changes observed in the oxidation potential and its resemblance with fluorescence quenching study in establishing the probable mechanism associated with the sensing study of HEMs (viz., RDX, PETN, CL-20 and RDX: CL-20 Cocrystal). FTIR and resonance Raman characterization helped us to understand the interaction between nitro groups present in HEMs with benzenoid unit or polaronic or bipolaronic nitrogen of camphor sulfonic acid doped polyaniline (CSA[PANi]). Employing Stern Volmer plot, the efficiency of quenching and quenching mechanisms of complex structure formed between the fluorophore and HEMs is understood.