Towards microsystems for automatic acquisition of in vivo gastrointestinal information

The possibility to develop a microanalysis system for the acquisition of gastrointestinal information is presented here. The system consists of four assay sites for trypsin, pepsin, and other biochemical compounds. The major components in each assay site were a pH-responsive valve, a pH-stat used to maintain the pH of the solution to be analyzed and used for electrochemical pH-titration, and a freeze-dried enzyme substrate stored in the pH-stat. The operation of the valve is based on electrowetting, and the valve is made pH-responsive by means of a nonstandard three-electrode system. The sample solution was automatically injected into the compartment and rapidly dissolved into the substrate layer. The automatic pH-stat, based on another nonstandard use of the electrochemical three-electrode system, maintained the solution pH and, at the same time, conducted pH-titration. The determination of the activity of the proteases was conducted at their optimum pHs. The output current showed a clear dependence on t...

[1]  R. Fair,et al.  Droplet-based microfluidic lab-on-a-chip for glucose detection , 2004 .

[2]  Joonwon Kim,et al.  Using EWOD (electrowetting-on-dielectric) actuation in a micro conveyor system , 2005 .

[3]  R. Fair,et al.  Electrowetting-based actuation of droplets for integrated microfluidics. , 2002, Lab on a chip.

[4]  D J Kim,et al.  An easily integrative and efficient micromixer and its application to the spectroscopic detection of glucose-catalyst reactions. , 2005, The Analyst.

[5]  R. Fair,et al.  An integrated digital microfluidic lab-on-a-chip for clinical diagnostics on human physiological fluids. , 2004, Lab on a chip.

[6]  Hans Ulrich Bergmeyer,et al.  Methods of Enzymatic Analysis , 2019 .

[7]  B. Berge,et al.  Electrowetting : a recent outbreak , 2001 .

[8]  Hiroshi Toshiyoshi,et al.  Light actuation of liquid by optoelectrowetting , 2003 .

[9]  Wataru Satoh,et al.  Microanalysis system with automatic valve operation, pH regulation, and detection functions , 2008 .

[10]  Wataru Satoh,et al.  On-chip microfluidic transport and mixing using electrowetting and incorporation of sensing functions. , 2005, Analytical chemistry.

[11]  S. Cho,et al.  Low voltage electrowetting-on-dielectric , 2002 .

[12]  Robin H. Liu,et al.  Passive mixing in a three-dimensional serpentine microchannel , 2000, Journal of Microelectromechanical Systems.

[13]  B. Ammori,et al.  Clinical laboratory assessment of acute pancreatitis. , 2005, Clinica chimica acta; international journal of clinical chemistry.

[14]  A. Manz,et al.  Microstructure for efficient continuous flow mixing , 1999 .

[15]  G. Kovacs.  Micromachined Transducers Sourcebook , 1998 .

[16]  Craig A. Grimes,et al.  Encyclopedia of Sensors , 2006 .

[17]  J. Baret,et al.  Electrowetting: from basics to applications , 2005 .

[18]  M. Hitchman,et al.  Evaluation of iridium oxide electrodes formed by potential cycling as pH probes. , 1988, The Analyst.

[19]  Isao Karube,et al.  Microfabricated Liquid Junction Ag/AgCl Reference Electrode and Its Application to a One-Chip Potentiometric Sensor , 1999 .

[20]  Sanjay Upadhyay,et al.  Electrochemical microsystem with porous matrix packed-beds for enzyme analysis , 2007 .

[21]  I. Mezić,et al.  Chaotic Mixer for Microchannels , 2002, Science.

[22]  W. Rick,et al.  Pepsin (Pepsin, Gastricsin, Pepsinogen, Uropepsinogen) , 1974 .

[23]  Juan G. Santiago,et al.  A review of micropumps , 2004 .

[24]  Katsuya Morimoto,et al.  Micro analysis system for pH and protease activities with an integrated sample injection mechanism. , 2006, Biosensors & bioelectronics.

[25]  Hiroaki Suzuki,et al.  Microfluidic transport based on direct electrowetting , 2004 .

[26]  Phil Paik,et al.  Rapid droplet mixers for digital microfluidic systems. , 2003, Lab on a chip.

[27]  Wataru Satoh,et al.  Electrochemical immunoassay on a microfluidic device with sequential injection and flushing functions. , 2007, Biosensors & bioelectronics.

[28]  Katsuya Morimoto,et al.  Automatic electrochemical micro-pH-stat for biomicrosystems. , 2008, Analytical chemistry.

[29]  S. Cosnier,et al.  Protease amperometric sensor. , 2006, Analytical chemistry.

[30]  Wataru Satoh,et al.  Integrated Electrochemical Analysis System with Microfluidic and Sensing Functions , 2008, Sensors.

[31]  R. Fair,et al.  Electrowetting-based actuation of liquid droplets for microfluidic applications , 2000 .

[32]  Piet Bergveld,et al.  Thirty years of ISFETOLOGY ☆: What happened in the past 30 years and what may happen in the next 30 years , 2003 .

[33]  G. Iddan,et al.  Wireless capsule endoscopy , 2003, Gut.

[34]  A. Murray,et al.  Toward a miniature wireless integrated multisensor microsystem for industrial and biomedical applications , 2002 .

[35]  Hiroaki Suzuki,et al.  Advances in the Microfabrication of Electrochemical Sensors and Systems , 2000 .

[36]  Wataru Satoh,et al.  Electrowetting-based valve for the control of the capillary flow , 2008 .

[37]  Victor M Ugaz,et al.  Multivortex micromixing. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[38]  Arianna Menciassi,et al.  Wireless capsule endoscopy: from diagnostic devices to multipurpose robotic systems , 2007, Biomedical microdevices.

[39]  Lei Wang,et al.  Implementation of radiotelemetry in a lab-in-a-pill format. , 2006, Lab on a chip.