Trace‐Level, Multi‐Gas Detection for Food Quality Assessment Based on Decorated Silicon Transistor Arrays

Abstract

and mass-sensitive sensors, [9] but few of these have been demonstrated to be cost, power, and size effective. For instance, the widely commercialized resistance-based metal oxide sensors must typically be operated at high temperatures to enable the adsorption interactions required for transduction. [8,[10][11][12] This results in higher power consumption as operation temperatures must be adjusted by a built-in heater. While other efforts have focused on the optimization of sensing materials [4,13,14] and sensor structure, [15] the resulting devices remain far from being practically applicable due to their limited detection sensitivity and poor reproducibility under mass fabrication. [16] Therefore, effective gas sensing systems with minimal baseline drift, good selectivity, low hysteresis, and the ability to simultaneously measure multiple gases still need to be developed. In this context, silicon transistor-based sensors have shown significant promise, with key advantages in overcoming size limitations, low power sensing, and high sensitivity, [17][18][19][20][21] making them useful for trace-level gas sensing applications required in food freshness monitoring.Ammonia (NH 3 ) and hydrogen sulfide (H 2 S) are two types of marker gases for spoiling food. For high-protein foods such as eggs, dairy, and meat, off-gassed NH 3 and H 2 S serve as quality indicators of freshness. [22][23][24][25] These gases can also be emitted from rotting vegetables such as corn and spinach. [26] For simplicity, eggs and pork samples are selected for monitoring food spoilage in this work. Based on reported data, 10 mL of egg whites produces ≈100 µg of H 2 S over multiple hours. [23] After accounting for food storage volume and temperature, this means that the sensor system must be able to identify H 2 S and NH 3 gases with lower than 100 ppb detection limits and negligible cross-sensitivity. While electrochemical, colorimetric, and other sensing schemes in previous work have shown promise for gas and adulteration detection, it still remains to detect gas signatures continually and at low concentration levels for monitoring spoiling food. [24][25][26][27][28][29] Multiplexed sensing is also important-for example, humidity is another important parameter that affects food storage and spoilage, [22,[30][31][32][33][34] and thus should be simultaneously monitored with H 2 S and NH 3 . All of these requirements necessitate the deployment of sensors with high selectivity and low detection limits.Multiplexed gas detection at room temperature is critical for practical applications, such as for tracking the complex chemical environments associated with food decomposition and spoilage. An integrated array of multiple silicon-based, chemical-sensitive field effect transistors (CSFETs) is presented to realize selective, sensitive, and simultaneous measurement of gases typically associated with food spoilage. CSFETs decorated with sensing materials based on ruthenium, silver, and silicon oxide are used to obtain stable room-temperature responses t...

Fully integrated ultra-sensitive electronic nose based on organic field-effect transistors

“…An automated control of food freshness by gas sensors requires resistivity to humidity and sensitivity towards volatile thiol-containing compounds, which are related to proteins decomposition at 100 ppb range 5 , 7 , 59 . Fast, sensitive and reusable sensors are long awaited in food industry to replace long and expensive bacteriological methods 4 , 60 .…”

Innovations in Smart Packaging Concepts for Food: An Extensive Review

“…An interesting class of devices that have been developed for very selective gas concentration detection in the headspace of food packaging are silicon-based optical transducers composed of optical circuits integrated in silicon semiconductor material [235].…”

Food Sensors: Challenges and Opportunities

“…Common markers for gas‐targeting food sensors include carbon dioxide, [ 31,43 ] oxygen, [ 44–48 ] volatile organic compounds (VOCs), [ 49–52 ] and biogenic amines (BAs). [ 21,53–56 ]…”

“…Yuan et al recently presented a low cost multiplex gas detection system that monitors ammonia, hydrogen sulfide, and humidity to track food decomposition. [21] The devices employ silicon-based chemically-sensitive field effect transistors that are decorated with sensing materials (ruthenium, silver, and silicon oxide) that produce sensitive and selective electronic responses to the targeted gases. The sensors are combined with a custom printed silicon-based circuit board to construct a portable device and the authors demonstrated the efficacy of the sensor by tracking the spoilage of pork belly.…”

“…Common markers for gas-targeting food sensors include carbon dioxide, [31,43] oxygen, [44][45][46][47][48] volatile organic compounds (VOCs), [49][50][51][52] and biogenic amines (BAs). [21,[53][54][55][56] Carbon dioxide is a product of bacterial metabolism and is also a preservative at high concentrations in modified atmosphere food packaging. Changes in the CO 2 concentration in food packaging can be used to detect food spoilage or package integrity.…”