scholarly journals Microsensors for In-Situ, Real-Time Detection and Characterization of Toxic Organic Substances

2001 ◽  
Author(s):  
S Rajic
Keyword(s):  
Real Time ◽  
Organic Substances ◽  
Real Time Detection ◽  
Toxic Organic Substances

scholarly journals Assembly of Conducting Polymer and Biohydrogel for the Release and Real-Time Monitoring of Vitamin K3

Gels ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 86 ◽  
Author(s):  
Brenda Molina ◽  
Eva Domínguez ◽  
Elaine Armelin ◽  
Carlos Alemán
Keyword(s):  
Real Time ◽  
Differential Pulse ◽  
Integrated System ◽  
Dual Function ◽  
Therapeutic Approaches ◽  
Vitamin K3 ◽  
Flexible Electrode ◽  
Anodic Synthesis

In this work, we report the design and fabrication of a dual-function integrated system to monitor, in real time, the release of previously loaded 2-methyl-1,4-naphthoquinone (MeNQ), also named vitamin K3. The newly developed system consists of poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles, which were embedded into a poly-γ-glutamic acid (γ-PGA) biohydrogel during the gelling reaction between the biopolymer chains and the cross-linker, cystamine. After this, agglomerates of PEDOT nanoparticles homogeneously dispersed inside the biohydrogel were used as polymerization nuclei for the in situ anodic synthesis of poly(hydroxymethyl-3,4-ethylenedioxythiophene) in aqueous solution. After characterization of the resulting flexible electrode composites, their ability to load and release MeNQ was proven and monitored. Specifically, loaded MeNQ molecules, which organized in shells around PEDOT nanoparticles agglomerates when the drug was simply added to the initial gelling solution, were progressively released to a physiological medium. The latter process was successfully monitored using an electrode composite through differential pulse voltammetry. The fabrication of electroactive flexible biohydrogels for real-time release monitoring opens new opportunities for theranostic therapeutic approaches.

In-Situ Real-Time Characterization of Particulate Emissions from a Diesel Engine Exhaust by Laser-Induced Incandescence

2000 ◽  
Author(s):  
David R. Snelling ◽  
Gregory J. Smallwood ◽  
Robert A. Sawchuk ◽  
W. Stuart Neill ◽  
Daniel Gareau ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Real Time ◽  
Particulate Emissions ◽  
Engine Exhaust ◽  
Diesel Engine Exhaust ◽  
Laser Induced Incandescence

Adsorption-Induced Surface Effects on the Dynamical Characteristics of Micromechanical Resonant Sensors for In Situ Real-Time Detection

2016 ◽  
Vol 83 (8) ◽  
Author(s):  
Kai-Ming Hu ◽  
Wen-Ming Zhang ◽  
Xi Shi ◽  
Han Yan ◽  
Zhi-Ke Peng ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Real Time ◽  
Surface Effects ◽  
Detection Sensitivity ◽  
Dynamical Model ◽  
Time Varying ◽  
Resonant Sensors ◽  
Label Free Detection ◽  
Real Time Detection

By incorporating modified Langmuir kinetic model, a novel slowly time-varying dynamical model of in situ micromechanical sensors is proposed to real-time monitor atomic or molecular adsorptions on the solid surface in a viscous fluid. First, Langmuir kinetic model is modified by the introduction of time-varying concentrations of analytes. Second, van der Waals (vdW), Coulomb, and biomolecular interactions for uncharged adsorbates, charged ones, and double-stranded DNAs (dsDNAs) are adopted, respectively, to develop the governing equation of time-varying vibrational systems with Hamilton's principle. It can be found that the adsorption-induced surface effects are incorporated into the dynamical equation of sensors due to real-time adsorptions. Third, the dynamical model is validated with the theoretical results of O atoms on Si (100) surface and the experimental data of dsDNAs interactions. The results show that the dynamical behavior is adsorption-induced slowly time-varying vibration due to the time-varying effective mass, stiffness, damping, and equilibrium positions of the microcantilevers. Moreover, comparing the modified Langmuir kinetic model with the unmodified model, the amplitude and phase hysteresis phenomena of frequency shift for resonant sensors can result in huge detection errors. In addition, the fluid effect can dramatically degrade the sensitivity and precision of real-time detection by several orders, which can provide a theoretical foundation to improve the detection sensitivity by reducing the fluid effect. The work demonstrates that it is essential to develop a time-varying dynamical model for in situ real-time label-free detection technique.

DEVELOPMENT OF AN EVANESCENT FIELD SYSTEM FOR REAL-TIME DETECTION OF DNA HYBRIDIZATION

2002 ◽  
Vol 01 (05n06) ◽  
pp. 663-666
Author(s):  
DO-KYUN KIM ◽  
YOUNG-SOO KWON ◽  
EIICHI TAMIYA
Keyword(s):  
Real Time ◽  
Dna Hybridization ◽  
Detection Method ◽  
Evanescent Field ◽  
Surface Excitation ◽  
Oligonucleotide Hybridization ◽  
Real Time Detection ◽  
Field Excitation ◽  
Hybridization Reaction

In this research, we report the characterization of the probe and target oligonucleotide hybridization reaction using the evanescent field microscopy. For detection of DNA hybridization assay, a high-density array of sensor probes were prepared by randomly distributing a mixture of particles immobilized with oligonucleotides for DNA chip applications. With the evanescent field excitation and real-time detection method, we suggest that a very sharp discrimination of bulk fluorescence against surface excitation in combination with high excitation intensities can be achieved.

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