scholarly journals Design of a Sandwich Hierarchically Porous Membrane with Oxygen Supplement Function for Implantable Glucose Sensor

2020 ◽  
Vol 10 (8) ◽  
pp. 2848 ◽  
Author(s):  
Lijuan Huang ◽  
Ziru Jia ◽  
Hongying Liu ◽  
Xitian Pi ◽  
Jiawen Zhou

This study aims to develop an oxygen regeneration layer sandwiched between multiple porous polyurethanes (PU) to improve the performance of implantable glucose sensors. Sensors were prepared by coating electrodes with platinum nanoparticles, Nafion, glucose oxidase and sandwich hierarchically porous membrane with an oxygen supplement function (SHPM-OS). The SHPM-OS consisted of a hierarchically porous structure synthesized by polyethylene glycol and PU and a catalase (Cat) layer that was coated between hierarchical membranes and used to balance the sensitivity and linearity of glucose sensors, as well as reduce the influence of oxygen deficiency during monitoring. Compared with the sensitivity and linearity of traditional non-porous (NO-P) sensors (35.95 nA/mM, 0.9987, respectively) and single porous (SGL-P) sensors (45.3 nA /mM, 0.9610, respectively), the sensitivity and linearity of the SHPM-OS sensor was 98.45 nA/mM and 0.9989, respectively, which was more sensitive with higher linearity. The sensor showed a response speed of five seconds and a relative sensitivity of 90% in the first 10 days and remained 78% on day 20. This sensor coated with SHPM-OS achieved rapid responses to changes of glucose concentration while maintaining high linearity for long monitoring times. Thus, it may reduce the difficulty of back-end hardware module development and assist with effective glucose self-management for people with diabetes.

Author(s):  
Lorna K. Mayo ◽  
Kenneth C. Moore ◽  
Mark A. Arnold

An implantable artificial endocrine pancreas consisting of a glucose sensor and a closed-loop insulin delivery system could potentially replace the need for glucose self-monitoring and regulation among insulin dependent diabetics. Achieving such a break through largely depends on the development of an appropriate, biocompatible membrane for the sensor. Biocompatibility is crucial since changes in the glucose sensors membrane resulting from attack by orinter action with living tissues can interfere with sensor reliability and accuracy. If such interactions can be understood, however, compensations can be made for their effects. Current polymer technology offers several possible membranes that meet the unique chemical dynamics required of a glucose sensor. Two of the most promising polymer membranes are polytetrafluoroethylene (PTFE) and silicone (Si). Low-voltage scanning electron microscopy, which is an excellent technique for characterizing a variety of polymeric and non-conducting materials, 27 was applied to the examination of experimental sensor membranes.


2017 ◽  
Vol 46 (30) ◽  
pp. 9918-9924 ◽  
Author(s):  
Yinlin Tong ◽  
Jiaying Xu ◽  
Hong Jiang ◽  
Feng Gao ◽  
Qingyi Lu

Novel core–shell Cu@polymer nanocomposites were synthesized through a one-step self-activated route and developed as nonenzymatic glucose sensor.


2019 ◽  
Vol 114 (11) ◽  
pp. 113506 ◽  
Author(s):  
L. X. Qian ◽  
H. Y. Liu ◽  
H. F. Zhang ◽  
Z. H. Wu ◽  
W. L. Zhang

NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950045
Author(s):  
Fang Sun ◽  
Lehong Xing ◽  
Xihui Yang ◽  
Hailiang Huang ◽  
Lina Ning

In this study, CuO films with hollow cubic cages were prepared by a facile two-step procedure consisting of electrodeposition synthesis and subsequent direct calcination. First, Cu2O nanocubes were fabricated on ITO substrate through a simple electrodeposition procedure. Then, Cu2O nanocubes were converted to CuO hollow cubic cages without obvious morphological change through direct calcination. The obtained CuO cubic cages serving as active materials illustrated a favorable performance for nonenzymatic glucose sensing with high sensitivity of [Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text] at a low applied potential of 0.50[Formula: see text]V, fast-response time (less than 3[Formula: see text]s), low detection limit of 1.0[Formula: see text][Formula: see text]M and wide linear range up from 2.0[Formula: see text][Formula: see text]M to 1.0[Formula: see text]mM ([Formula: see text]). Moreover, the good selectivity of the CuO cubic cages-based nonenzymatic glucose sensor against electroactive compounds such as ascorbic acid, uric acid and dopamine were also demonstrated. These good features indicate that the as-prepared CuO cubic cages can be used as promising electrode materials, which have a great potential in the development of sensitive and selective nonenzymatic glucose sensors.


2020 ◽  
Vol 8 ◽  
Author(s):  
Yating Chen ◽  
Yulan Tian ◽  
Ping Zhu ◽  
Liping Du ◽  
Wei Chen ◽  
...  

Continuous intensive monitoring of glucose is one of the most important approaches in recovering the quality of life of diabetic patients. One challenge for electrochemical enzymatic glucose sensors is their short lifespan for continuous glucose monitoring. Therefore, it is of great significance to develop non-enzymatic glucose sensors as an alternative approach for long-term glucose monitoring. This study presented a highly sensitive and selective electrochemical non-enzymatic glucose sensor using the electrochemically activated conductive Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 MOFs as sensing materials. The morphology and structure of the MOFs were investigated by scanning SEM and FTIR, respectively. The performance of the activated electrode toward the electrooxidation of glucose in alkaline solution was evaluated with cyclic voltammetry technology in the potential range from 0.2 V to 0.6 V. The electrochemical activated Ni-MOFs exhibited obvious anodic (0.46 V) and cathodic peaks (0.37 V) in the 0.1 M NaOH solution due to the Ni(II)/Ni(III) transfer. A linear relationship between the glucose concentrations (ranging from 0 to 10 mM) and anodic peak currents with R2 = 0.954 was obtained. It was found that the diffusion of glucose was the limiting step in the electrochemical reaction. The sensor exhibited good selectivity toward glucose in the presence of 10-folds uric acid and ascorbic acid. Moreover, this sensor showed good long-term stability for continuous glucose monitoring. The good selectivity, stability, and rapid response of this sensor suggests that it could have potential applications in long-term non-enzymatic blood glucose monitoring.


2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Yuqiao Zeng ◽  
Hua Xiang ◽  
Chunlei Yang ◽  
Shengchen Yang ◽  
Luyang Chen ◽  
...  

We report the formation of enzyme-free electrochemical glucose sensors by electrochemical dealloying palladium-containing Pd-Ni-P metallic glasses. When metallic glasses with different Pd contents are used as the dealloying precursor alloys, palladium-based nanoporous metals with different ligament and pore sizes can be obtained. The chemical compositions of the nanoporous metals also vary according to the different precursor compositions. All the as-obtained nanoporous metals exhibit electrochemical catalytic activity towards the oxidation of d-glucose, indicating that the nanoporous metals prepared by dealloying the Pd-Ni-P metallic glasses are promising materials for enzyme-free electrochemical glucose sensor.


1996 ◽  
Vol 16 (11) ◽  
pp. 6419-6426 ◽  
Author(s):  
S Ozcan ◽  
T Leong ◽  
M Johnston

The RGT1 gene of Saccharomyces cerevisiae plays a central role in the glucose-induced expression of hexose transporter (HXT) genes. Genetic evidence suggests that it encodes a repressor of the HXT genes whose function is inhibited by glucose. Here, we report the isolation of RGT1 and demonstrate that it encodes a bifunctional transcription factor. Rgt1p displays three different transcriptional modes in response to glucose: (i) in the absence of glucose, it functions as a transcriptional repressor; (ii) high concentrations of glucose cause it to function as a transcriptional activator; and (iii) in cells growing on low levels of glucose, Rgt1p has a neutral role, neither repressing nor activating transcription. Glucose alters Rgt1p function through a pathway that includes two glucose sensors, Snf3p and Rgt2p, and Grr1p. The glucose transporter Snf3p, which appears to be a low-glucose sensor, is required for inhibition of Rgt1p repressor function by low levels of glucose. Rgt2p, a glucose transporter that functions as a high-glucose sensor, is required for conversion of Rgt1p into an activator by high levels of glucose. Grr1p, a component of the glucose signaling pathway, is required both for inactivation of Rgt1p repressor function by low levels of glucose and for conversion of Rgt1p into an activator at high levels of glucose. Thus, signals generated by two different glucose sensors act through Grr1p to determine Rgt1p function.


2016 ◽  
Vol 879 ◽  
pp. 1135-1140
Author(s):  
Thilo Liebscher ◽  
Franziska Glös ◽  
Andrea Böhme ◽  
M. Birkholz ◽  
M. di Vona ◽  
...  

With the growing demand of miniaturization of cell cultivation a new approach towards measuring and sensing bio-analytes needs to be made due to the problem of small volumes (less than 150μl) containing small amounts of analytes. Most of the available glucose sensors monitor the glucose concentration with the help of enzymes, which become very inaccurate in terms of long time measurement and uses (i.e. consumes) glucose during the measurement becoming not available anymore for the cells. Therefore, we focused on applying an enzyme-free glucose sensor based on a microelectromechanical system (MEMS).


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