Design and Fabrication of a Gas Sensor Based on a Polypyrrole/Silver Nanoparticle Film for the Detection of Ammonia in Exhaled Breath of COVID-19 Patients Suffering from Acute Kidney Injury

Abstract

One of the serious complications of COVID-19 is acute kidney injury (AKI), leading to a decrease in kidney function and even death. The concentration of ammonia (NH 3 ) in the exhaled breath (EB) of COVID-19 patients suffering from AKI symptoms will be significantly increased. In this work, the detection of breath NH 3 was performed at gold interdigital electrodes modified with a soluble polypyrrole microparticle and silver nanoparticle film (Au-IDEs/S-PPyMPs/AgNPs) as a noninvasive chemiresistor gas sensor. The response behavior of unmodified and modified gas sensors toward NH 3 and other interfering compounds was studied. The Au-IDEs/S-PPyMPs/AgNPs exhibited NH 3 detection in the linear dynamic range of 1.00−19.23 ppm, with a limit of detection of 0.12 ppm. Finally, the fabricated gas sensor was used to monitor the NH 3 concentration in the EB of COVID-19 patients suffering from AKI symptoms. For this purpose, the gas sensor was validated in 19 EB samples (seven COVID-19−positive patients, four COVID-19−negative patients, and eight post−COVID-19 patients). The gas sensor was directly exposed to the EB samples, followed by recording the changes in electrical resistance via a low-cost digital multimeter. The sensing mechanism was explained as the interaction between breath NH 3 and sensing materials. The breath NH 3 concentrations have a desirable correlation (R 2 = 0.8463) with the estimated glomerular filtration rate (eGFR) values in COVID-19−positive patients. The fabricated gas sensor can distinguish COVID-19−positive patients suffering from AKI symptoms from COVID-19−negative patients and post−COVID-19 patients. The present work can pave the way for the development of a simple and efficient analytical approach for COVID-19 patients with AKI without the need for sample pretreatment.

Chemiresistive sensor for breath frequency and ammonia concentration in exhaled gas over a PVA/PANI/CC composite film

“…33 This competitive adsorption of ammonia in humid condition promises a huge potential to measure the relative composition of both the gases, i.e., ammonia and water molecules, for different applications, which include medical techniques for chronic diseases, covid infection, and nephropathy diagnosis, but neither were systematically studied or commercialized for the betterment of medical diagnosis, as per our observation. 14,34,35 In the context of the above discussion, the present work reports the synergistic evolution of the humidity-responsive nature and hydrophilicity in an electrically conducting PVA/ PANI/CC composite. Further, the composite coated on a commercial mask was used for the monitoring of respiratory frequency and ammonia concentration in breath-out gases to screen the kidney condition of a healthy and an ill person.…”

“…, ammonia and water molecules, for different applications, which include medical techniques for chronic diseases, covid infection, and nephropathy diagnosis, but neither were systematically studied or commercialized for the betterment of medical diagnosis, as per our observation. 14,34,35…”

Bioelectronic Applications of Intrinsically Conductive Polymers

“…PPy is also studied in biochemical sensors, particularly for the detection of the amine‐based compounds because the absorption of the amine molecules can dedope PPy; and thus, increase its resistance. [ 132 ] For instance, Kamalabadi et al. fabricated a sensor using PPy microparticles and silver nanoparticles to detect ammonia released in the exhaled breath of COVID‐19 patients (Figure 12b).…”

“…Reproduced with permission. [ 132 ] 2022, American Chemical Society. c) An electrochemical biosensor with PDA@CNTs/PEDOT as the electrodes for dopamine sensing.…”

Microflowers Composed of VO2 Nanoflakes for Selective Detection of Acetone and Ammonia

“…32,33 In fact, humans also produce very low levels of acetone and ammonia during respiration, which are considered to be two major markers of diabetes and kidney disease, respectively. 34,35 Monitoring the levels of acetone and ammonia in exhaled breath will help us to detect and treat these two diseases more quickly. Therefore, the development of gas sensors that can effectively detect these two gases is deeply demanded nowadays for human health.…”