A Novel Non-Enzymatic Glucose Biofuel Cell with Mobile Glucose Sensing

Herein, we report a novel non-enzymatic glucose biofuel cell with mobile glucose sensing. We characterized the power generation and biosensing capabilities in presence of glucose analyte. This system was developed using a non-enzymatic glucose biofuel cell consisting of colloidal platinum coated gold microwire (Au-co-Pt) employed as an anode and the cathode which was constructed using a Gas diffusion electrode (GDE) with a platinum catalyst. The non-enzymatic glucose biofuel cell produced a maximum open circuit voltage of 0.54 V and delivered and a maximum short circuit current density of 1.6 mA/cm2 with a peak power density of 0.226 mW/cm2 at a concentration of 1 M glucose. The non-enzymatic glucose biofuel cell produced an open circuit voltage of 0.38 V and delivered and a short circuit current density of 0.225 mA/cm2 with a peak power density of 0.022 mW/cm 2 at a concentration of 5 mM glucose. These findings showed that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor. When used as self-powered glucose sensor, the system showed a good sensitivity of 0.616 μA mM−1 and linear dependence with a correlation coefficient of 0.995 in the glucose concentration range of 2 mM to 50 mM. The system was further characterized by testing the performance of the system at various temperature, pH and amidst various interfering and competing chemical species such as uric acid, ascorbic acid, fructose, maltose and galactose. A charge pump circuit consisting of a blinking LED was connected to the biofuel cell to amplify the input voltage to power small electronic devices. The blinking frequency of the LED corresponds to the glucose concentration. An android mobile phone camera application was used to measure this LED blinking frequency which was in turn converted into the glucose concentration readings using image processing in MATLAB. The user was notified via text message and an email

A Fully-Flexible Solution-Processed Autonomous Glucose Indicator

We present the first demonstration of a fully-flexible, self-powered glucose indicator system that synergizes two flexible electronic technologies: a flexible self-powering unit in the form of a biofuel cell, with a flexible electronic device - a circuit-board decal fabricated with biocompatible microbial nanocellulose. Our proof-of-concept device, comprising an enzymatic glucose fuel cell, glucose sensor and a LED indicator, does not require additional electronic equipment for detection or verification; and the entire structure collapses into a microns-thin, self-adhering, single-centimeter-square decal, weighing less than 40 mg. The flexible glucose indicator system continuously operates a light emitting diode (LED) through a capacitive charge/discharge cycle, which is directly correlated to the glucose concentration. Our indicator was shown to operate at high sensitivity within a linear glucose concentration range of 1 mM-45 mM glucose continuously, achieving a 1.8 VDC output from a flexible indicator system that deliver sufficient power to drive an LED circuit. Importantly, the results presented provide a basis upon which further development of indicator systems with biocompatible diffusing polymers to act as buffering diffusion barriers, thereby allowing them to be potentially useful for low-cost, direct-line-of-sight applications in medicine, husbandry, agriculture, and the food and beverage industries

Self-Powered Electrochemical Lactate Biosensing

This work presents the development and characterization of a self-powered electrochemical lactate biosensor for real-time monitoring of lactic acid. The bioanode and biocathode were modified with D-lactate dehydrogenase (D-LDH) and bilirubin oxidase (BOD), respectively, to facilitate the oxidation and reduction of lactic acid and molecular oxygen. The bioelectrodes were arranged in a parallel configuration to construct the biofuel cell. This biofuel cell’s current–voltage characteristic was analyzed in the presence of various lactic acid concentrations over a range of 1–25 mM. An open circuit voltage of 395.3 mV and a short circuit current density of 418.8 µA/cm² were obtained when operating in 25 mM lactic acid. Additionally, a 10 pF capacitor was integrated via a charge pump circuit to the biofuel cell to realize the self-powered lactate biosensor with a footprint of 1.4 cm × 2 cm. The charge pump enabled the boosting of the biofuel cell voltage in bursts of 1.2–1.8 V via the capacitor. By observing the burst frequency of a 10 pF capacitor, the exact concentration of lactic acid was deduced. As a self-powered lactate sensor, a linear dynamic range of 1–100 mM lactic acid was observed under physiologic conditions (37 °C, pH 7.4) and the sensor exhibited an excellent sensitivity of 125.88 Hz/mM-cm2. This electrochemical lactate biosensor has the potential to be used for the real-time monitoring of lactic acid level in biological fluids

Simultaneous Monitoring of Glucose and Lactate by Self-powered Biosensor

A dual self-powered biosensing system integrated with energy amplification circuit is described, for simultaneously monitoring glucose and lactate. The self-powered biosensing system is based on the conventional enzymatic biofuel cell equipped with three 4 mm x 4 mm massively dense mesh network of multi-walled carbon nanotubes (MWCNTs) bioelectrodes in parallel configuration. The bioelectrodes employed pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) as the biocatalyst for the glucose oxidation and D-Lactate dehydrogenase (D-LDH) as the biocatalyst for lactate oxidation. A common laccase modified-MWCNTs bioelectrode served as the cathode for the reduction of molecular oxygen. Two charge pump circuits were coupled with 0.1 mF capacitors functioning as transducers. The advantages of employing capacitors were coupled with the efficient energy amplification of the charge pump circuit to amplify the power output from each of the biofuel and charge/discharge the corresponding capacitor. Under operating conditions, the open circuit voltages and short circuit current densities for 180 mg/dL glucose and 25 mM lactate were 339.2 mV and 228.75 µA/cm2 and 370 mV and 66.17 µA/cm2, respectively. The responses for glucose and lactate were linear up to 630 mg/dL and 30 mM with sensitivities of 20.11 Hz/ mM cm-2 and 9.869 Hz/ mM cm-2, respectively. The potential of the described system was demonstrated to provide stable voltage and current output that was capable of driving the charge pump circuit integrated with the capacitor for simultaneously monitoring glucose and lactate. These results were in good agreement with those previously reported

Sensitive electrochemical detection of glucose via a hybrid self-powered biosensing system

The importance of glucose in many biological processes continues to garner increasing research interest in the design and development of efficient biotechnology for the sensitive and selective monitoring of glucose. Here we report on a novel hybrid self-powered biosensing system with a unique capability to convert the biochemical energy of glucose into electrical power, which is subsequently stored in a 10 pF capacitor serving as the transducing element. The anode and biocathode of the hybrid cell were constructed from a gold-supported nanoporous colloidal platinum structure (Au-co-Pt) and bilirubin oxidase (BOD) modified gold coated Buckypaper (BP-Au-BOD), respectively. The hybrid cell delivered an open circuit voltage and short circuit current of 0.73 V and 0.50 mA, which was ample to drive an energy amplification circuit and generate sufficient power to power an LED via the 10 pF capacitor. The self-powered glucose biosensing system exhibited excellent electrocatalytic activity towards glucose oxidation with a linear dynamic range up to 18 mM glucose. The biosensor demonstrated excellent selectivity towards glucose in the presence of interfering species. This presented hybrid self-powered biosensing system holds great promise to develop a self-contained continuous monitoring systems for a variety of biomedicine applications. Keywords: Biofuel cell, Energy harvesting, Bilirubin oxidase, Self-powered glucose biosensing, Electrochemical senso