No abstract

Knowledge of transduction mechanisms in biosensing applications paves the way for ultrasensitive and dynamic detection in living systems. Real-world biosensing applications where ultrasensitivity and dynamic detection are paramount include monitoring the anesthetic agent concentration during surgery; the slightest variation in concentration can potentially result in a life-threatening overdose or, on the other end of the spectrum, the patient's awareness during the procedure. We review the benefits and functions of the transcutaneous biosensor device compared with other current technology and discuss the sensor's capability to accurately measure volatile anesthetic gas concentration in blood using fuel cell technology. We review fundamental concepts of fuel-cell technology for bio-sensing applications. The fuel cell sensor can also continuously monitor other volatile organic compounds making it versatile with numerous potential applications.

In surgical procedures, it is vital to keep the anesthetic agent concentration appropriate as a slight variation can cause either an overdose or awareness in the surgery. Most of the anesthesia apparatuses in current practice do not have a system for monitoring the anesthetic agent's concentration; therefore, a convenient anesthetic monitor to continuously measure the concentration is highly expected. The widely used inhalational anesthesia, isoflurane (1-chloro-2,2,2-trifluoromethyl difluoromethyl ether) is colorless, volatile, and nonflammable. Therefore to maintain the anasthesia, complex machines equipped with vaporizers and infrared (IR) sensors are used to deliver the required dose of isoflurane. However, existing IR analyzers for the isoflurane have to be operated with highly precise optical alignments, which find limited deployment for critical care in low resource environments due to size, cost, and complexity. Results from controlled or uncontrolled administration of the anesthetic bring serious negative health outcomes. There is an urgent unmet clinical need to cost-effectively ensure the patient's safety and the personnel exposed in the operating room. We are developing a transcutaneous isoflurane biosensor device that can accurately measure volatile anesthetic gas concentration in blood at a much lower cost/unit to address this unmet need. Our approach consists of using micro-fuel cell Transcutaneous Anesthesia Monitoring Systems (TAMS). Micro-fuel cell TAMS is the simplest form of an electrochemical device composed of a Proton Exchange Membrane (PEM) sandwiched between two metal electrodes. In micro-fuel cell TAMS sensing application, an electrical current is directly generated to the isoflurane concentration. Comparing to the existing IR analyzers, micro-fuel cell TIMS is much smaller but more robust. It can be easily deployed for applications under various environmental applications. This easy-to-use, low-cost anesthetic sensing system will provide the patients' safety during surgical procedures, even in low-resource settings in the developing world. We propose the micro-fuel cell TAMS for cost-effectively and continuously accurate anesthesia detection.