Synthesis of polyaniline (printable nanoink) gas sensor for the detection of ammonia gas Pukhrambam Dipak 1, *, Dinesh Chandra Tiwari 1,2, * , Anuradha Samadhiya 2 , Neeraj Kumar 3 , Thingom Biswajit 4 , Pukhrambam Akash Singh 5 , and Rajendra Kumar Tiwari 1 1 School of Studies in Physics, Jiwaji University, Gwalior, India 2 School of Studies in Electronics, Jiwaji University, Gwalior, India 3 School of Studies in Chemistry, Jiwaji University, Gwalior, India 4 Department of Electronics, Dhanamanjuri University, Imphal, India 5 Department of Electrical Engineering, NIT-Manipur, Imphal, India Received: 4 June 2020 Accepted: 26 October 2020 Ó Springer Science+Business Media, LLC, part of Springer Nature 2020 ABSTRACT Here we are reporting the printable nanoink of polyaniline (PANI) which can be printed over the flexible substrate. The printed patterns (flexible) are used for the detection of toxic ammonia gas. The conducting polymer polyaniline (PANI) is synthesized by the chemical oxidative polymerization of aniline. The syn- thesized PANI is characterized by FTIR, UV–visible, XRD, FESEM and TEM. The FESEM and TEM micrograph shows the formation nanotubes of the PANI having the average diameter of 10.85 nm and average length of 45.6 nm. The XRD analysis revealed the PANI is between amorphous nature and crystalline. The synthesized PANI has the optical energy band gap of 2.9 eV. The printed pattern of PANI has able to detect the lowest concentration of 2.5 ppm of ammonia gas. It has the sensing response of 75%, with response time of 110 s and recovery time of 55 s at 2.5 ppm concentration. The sensor has the sensi- tivity of 1.0036 ppm -1 . 1 Introduction Monitoring of harmful gases present in the environ- ment became very important to the present world, which it directly or indirectly affects the living organism. To monitor the level of toxic gases present in the environment many scientists and researchers have developed different types of gas sensors work- ing at different mechanism. Some of the toxic gases are odorless which cannot be detected by human nose. Thus we have to develop the electronic nose which it can detect and convert to the electrical sig- nal. The ideal gas sensors should have the following characteristic such as operated at room temperature, low detection limit, working at ambient environment, high sensitivity, fast response and recovery, low cost and eco-friendly [1]. Recently (May, 2020, India) a styrene and hydrogen sulphide gas are leaked at Address correspondence to E-mail: pukchaokhuman@gmail.com; dctiwari2001@yahoo.com https://doi.org/10.1007/s10854-020-04760-2 J Mater Sci: Mater Electron