Wireless powered flexible carbon dioxide gas monitoring device utilizing polyethyleneimine functionalized GO/MXene composites for nondestructive dynamic monitoring of mango ripeness

Mangoes are usually packed in cardboard boxes during transportation and storage, and manual unpacking of the boxes to determine their ripeness is an inefficient method of testing. Fortunately, changes in carbon dioxide (CO₂) concentration can serve as an indicator of ripeness and potential spoilage. To address this, a wireless powered flexible CO₂ gas monitoring device (WFCMD) utilizing polyethyleneimine (PEI)-functionalized GO/MXene composites was developed. This device demonstrates high sensitivity and excellent electrical conductivity, making it suitable for real-time monitoring in practical applications. The response of the composites to CO₂ was evaluated with varying PEI loadings, showing enhanced sensing performance due to the efficient CO₂ adsorption by PEI and the high conductivity of GO/MXene. The complete gas monitoring system was integrated using an ESP-12F microcontroller unit (MCU), allowing for seamless attachment to the surface of mangoes for continuous, nondestructive monitoring. The device's feasibility was confirmed through extended monitoring of packaged mangoes, demonstrating its potential for application in fruit gas detection and quality control.