The synergism between the structure and property of polymer composite is a key feature for expanding the spectrum of their applications. In general, polymers have natural uncertainty in their structure concerning chain length, molecular mass, shapes, and functionality, which allows them to be used or restricted for precise applications. In this context, several modifications are proposed to modify the structure and properties of polymers to enhance their usability in active and passive applications. Currently, advantageous features of polymers viz. processability, responsiveness, and induced functionality have been explored in several sensing sciences. In different types of sensing applications, the precise determination of pharmaceuticals is very important for drug monitoring, synthetic organic chemistry, forensic science, and environmental chemistry for industrial growth, and human and animal health. The overconsumption, production of pharmaceuticals, and ill practices major contributors to water pollution and environmental issues. It has been reported that exposure to active pharmaceutical ingredients can lead to a deleterious effect on the health of living organisms as well as the ecosystem [1,2]. The major water-polluting pharmaceuticals are Erythromycin, Metaflumizone, Azithromycin, Methiocarb, Imidacloprid, Thiacloprid, Clothianidin, Ibuprofen, Clarithromycin, Acetamiprid, Amoxicillin, Ciprofloxacin, Sulfamethoxazole, Thiamethoxam, and their metabolites. Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug, which is used as a painkiller in menstrual cramps, and arthritis and antipyretic agent. Although IBU is less toxic, its overdose and excess consumption still lead to serious problems like heart attack [[3], [4], [5]], block the activity of cyclooxygenase, and inhibit the working of prostaglandin [6]. It has also been reported that the excess consumption of IBU leads to huge non-metabolite fractions, which end up in the sewage and water treatment plants, which is responsible for the pollution of water and water-produced edible items [7,8].

Therefore, various analytical techniques including High-Performance Liquid Chromatography [9], electrochemical sensing [[10], [11], [12]] titrimetric, spectroscopy [13,14], and chemiluminescence [15] have been explored for the detection of IBU with their merit and demerits [16]. Among the different analytical methods, the electrochemical method has been established as the most promising one due to its portability, reliability, stability, and sensing performance [17]. The reliability of this method depends on the used sensing material, which is either metal or metal oxides [[18], [19], [20]], conducting polymers, biopolymers, and their hybrids. Conducting polymer composites [21,22] proved to be advantageous due to their bio-compatibility, stability, novel catalytical activity, electrical properties, and structural manipulation [23]. The presence of metal oxide in a conducting polymer hybrid provides increased crystallinity, and porosity, and provides better interaction sites for ibuprofen sensing as listed in Table 1. The variable electron-accepting nature of metal ions is also responsible for optimizing the resulting polymeric structure and formation of multiple oxidation states and functionality. Kushwaha et al. [24] have synthesized ferric oxide doped chitosan grafted polyaniline composite for the electrochemical sensing of paracetamol and reported the sensitivity of the developed sensor with limited features. Polyaniline provides significant properties, however, polypyrrole (PPy) and its composites also prove to be better sensing materials because of higher responsiveness and stability than polyaniline [25]. The hybrid structure of PPy along with metal oxides has been reported by several researchers [26] with properties and use in sensing applications but a tripartite relation between structure, properties, and sensing application still needs to be established. In the context of the above development, the present paper reports the synthesis of a ternary hybrid composite consisting of iron oxide, chitosan, and polypyrrole for the electrochemical sensing of IBU after correlating the structure of composite evolved properties, and their impact on the sensing behavior of IBU in laboratory designed sensing setup without external energy. The proposed composite exhibits good sensitivity, improved stability, improved electrical conductivity, and porosity due to the evolution of axial-aligned crystallinity and hybrid matrix.