ORIGINAL PAPER Hydrazine sensor based on silver nanoparticle-decorated polyaniline tungstophosphate nanocomposite for use in environmental remediation Mohammed M. Rahman 1,2 & Anish Khan 1,2 & Hadi M. Marwani 1,2 & Abdullah M. Asiri 1,2 Received: 17 December 2015 /Accepted: 25 February 2016 # Springer-Verlag Wien 2016 Abstract A nanocomposite consisting of silver nanoparticle- decorated polyaniline and tungstophosphate was deposited on a glassy carbon electrode to result in an improved electro- chemical sensor for dissolved hydrazine by the I-V (current– voltage) technique. The sensor, if operated at +0.5 V, has a fast response time (10 s), good sensitivity (~12.5 μA⋅mM -1 ⋅cm -2 ) and long-term stability. Response to hydrazine is linear in the 10 nM to 10 mM concentration range, and the detection limit is 2.8 nM at a signal-to-noise ratio of 3. Keywords Tungstophosphate-PAni . Silver nanocomposite . Hydrazine . Conductive polymer . I-V method . Glassy carbon electrode . Field-emission scanning electron microscopy . Energy dispersive spectroscopy Introduction Hydrazine is extensively utilized as antioxidant, corrosion in- hibitor, rocket fuel, and in the preparation of catalysts, emul- sifiers, reducing agents, pesticides, and plant growth regula- tors [1, 2]. It is a neurotoxin, and hence produces carcinogenic and mutagenic effects causing damage to lungs, liver, and kidneys, respiratory tract infection and long-term effects on the central nervous system [3]. In pharmaceuticals also, it has much significance as it has been acknowledged as carcinogen- ic and hepatotoxic chemicals which affects the liver and brain [ 4]. Electro-oxidation of hydrazine is the basis of an established fuel cell, owing to its high capacity and no con- tamination. In addition to this, hydrazine is widely used as high-energy propellants in rockets and spacecrafts by military and aerospace industries [5]. Owing to aforementioned appli- cations in industry, environment and pharmacology, it is very significant to fabricate a reliable, cheap and effective tech- nique for the efficient detection of hydrazine. Among several detection methodologies, the electrochemical I-V method of- fers an opportunity for portable, cheap and rapid methodolo- gies. Therefore, numerous chemically modified electrodes, based on different nanostructure materials, semiconductor doped or undoped nanomaterials, transition metal oxides, electrocatalytic moieties (electron-mediator species), has thus been developed for the detection of hydrazine and reported in the literature [6]. Recently, scientists have demonstrated the use of semiconductor nanostructures as electron mediators to modify the electrodes for the electrochemical detection of tox- ic hydrazine [7, 8]. Conducting polymers (polyaniline, PAni) is good materials for chemical sensor development by doping various metallic parts due to their excellent surface area, mesoporous nature, easy synthesis, high catalytic property and good chemical sta- bility. The shortcoming of these polymer nanocomposites is the porous that occurs due to its swelling and shrinking during preparation of composites with various inorganic counter parts. This occurs because the incorporation of metallic ions causes a current change in the polymer matrixes. Hybrid organic/inorganic materials in general represent the natural interface between two worlds of material science. The main challenge is managing to synthesize inorganic–organic hybrid combinations that keep or enhance the best properties of each of the components while eliminating or reducing their * Mohammed M. Rahman mmrahman@kau.edu.sa 1 Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia 2 Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia Microchim Acta DOI 10.1007/s00604-016-1809-4