Jacobs Aaron I, Prete Maiyara C, Lesch Andreas, Sebio Angel Abuelo, Teixeira Tarley César Ricardo, Swain Greg M
Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States.
Department of Chemistry, State University of Londrina (UEL), Londrina, Paraná 86051-990, Brazil.
ACS Omega. 2024 Sep 16;9(39):40841-40856. doi: 10.1021/acsomega.4c05800. eCollection 2024 Oct 1.
The collection, processing, and electrochemical analysis of exhaled breath condensate (EBC) from healthy human and animal subjects is reported on. EBC is a biospecimen potentially rich in biomarkers of respiratory disease. The EBC pH was analyzed potentiometrically using a disposable polyaniline (PANI)-modified inkjet-printed (IJP) carbon electrode. Comparison measurements were performed using a commercial screen-printed carbon (SPC) electrode. The PANI-modified electrodes exhibited reproducible and near-Nernstian responses for pH values between 2 and 9 with slopes from -50 to -60 mV/dec. The PANI-modified IJP carbon electrode exhibited a faster response time and superior reproducibility to the modified SPC electrode. In proof-of-concept studies, the healthy human EBC pH was found to be 6.57 ± 0.09 and the healthy bovine EBC pH was 5.9 ± 0.2. All pH determined using the PANI-modified electrodes were in good agreement with the pH determined using a micro glass pH electrode. An RTube device was used to collect EBC from humans while a modified device was used to collect EBC from calves in the field. EBC volumes of 0.5-2 mL for 5-6 min of tidal breathing were collected from healthy animals. The pH of EBC from healthy calves (17 animals) depends on their age from 1 to 9 weeks with values ranging from 5.3 to 7.2. A distinct alkaline shift was observed for many animals around 20 days of age. The bovine EBC pH also depends on the ambient temperature and humidity at the time of collection. The results indicate that the PANI-modified IJP carbon electrodes outperform commercial SPC and provide reproducible and accurate measurement of pH across various biospecimen types.
本文报道了对健康人类和动物受试者呼出气体冷凝物（EBC）的收集、处理及电化学分析。EBC是一种可能富含呼吸系统疾病生物标志物的生物样本。使用一次性聚苯胺（PANI）修饰的喷墨打印（IJP）碳电极对EBC的pH进行电位分析。使用商用丝网印刷碳（SPC）电极进行对比测量。PANI修饰电极在pH值2至9之间表现出可重复且接近能斯特响应，斜率为-50至-60 mV/dec。PANI修饰的IJP碳电极比修饰的SPC电极响应时间更快且重现性更好。在概念验证研究中，发现健康人类EBC的pH为6.57±0.09，健康牛EBC的pH为5.9±0.2。使用PANI修饰电极测定的所有pH值与使用微型玻璃pH电极测定的pH值高度一致。使用RTube装置从人类收集EBC，同时使用改良装置在现场从小牛收集EBC。从健康动物进行5 - 6分钟潮式呼吸收集到的EBC体积为0.5 - 2 mL。健康小牛（17只动物）EBC的pH值取决于其1至9周龄，范围为5.3至7.2。在约20日龄时，许多动物出现明显的碱性转变。牛EBC的pH值还取决于采集时的环境温度和湿度。结果表明，PANI修饰的IJP碳电极优于商用SPC电极，能够对各种生物样本类型的pH进行可重复且准确的测量。
