In situ real-time detection of E. coli in water using antibody-coated magnetostrictive microcantilever

2010 ◽  
Vol 150 (1) ◽  
pp. 220-225 ◽  
Author(s):  
Liling Fu ◽  
Kewei Zhang ◽  
Suiqiong Li ◽  
Yuhong Wang ◽  
Tung-Shi Huang ◽  
...  
Keyword(s):  
Real Time ◽  
E Coli ◽  
Real Time Detection

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.

scholarly journals Near Real-Time Detection of E. coli in Reclaimed Water

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2303 ◽  
Author(s):  
Samendra Sherchan ◽  
Syreeta Miles ◽  
Luisa Ikner ◽  
Hye-Weon Yu ◽  
Shane Snyder ◽  
...  
Keyword(s):  
Light Scattering ◽  
Real Time ◽  
Detection System ◽  
Reclaimed Water ◽  
Organic Matter Content ◽  
Fluorescence Emission ◽  
Matter Content ◽  
Bacterial Populations ◽  
E Coli ◽  
Real Time Detection

Advanced treatment of reclaimed water prior to potable reuse normally results in the inactivation of bacterial populations, however, incremental treatment failure can result in bacteria, including pathogens, remaining viable. Therefore, potential microorganisms need to be detected in real-time to preclude potential adverse human health effects. Real-time detection of microbes presents unique problems which are dependent on the water quality of the test water, including parameters such as particulate content and turbidity, and natural organic matter content. In addition, microbes are unusual in that: (i) viability and culturability are not always synonymous; (ii) viability in water can be reduced by osmotic stress; and (iii) bacteria can invoke repair mechanisms in response to UV disinfection resulting in regrowth of bacterial populations. All these issues related to bacteria affect the efficacy of real-time detection for bacteria. Here we evaluate three different sensors suitable for specific water qualities. The sensor A is an on-line, real-time sensor that allows for the continuous monitoring of particulates (including microbial contaminants) using multi-angle-light scattering (MALS) technology. The sensor B is a microbial detection system that uses optical technique, Mie light scattering, for particle sizing and fluorescence emission for viable bacteria detection. The last sensor C was based on adenosine triphosphate (ATP) production. E. coli was used a model organism and out of all tested sensors, we found the sensor C to be the most accurate. It has a great potential as a surrogate parameter for microbial loads in test waters and be useful for process control in treatment trains.

In situ, real-time detection of soot particles coated with NaCl using 193 nm light

2006 ◽  
Vol 84 (3) ◽  
pp. 385-388
Author(s):  
J.H. Choi ◽  
C.B. Stipe ◽  
C.P. Koshland ◽  
D. Lucas
Keyword(s):  
Real Time ◽  
Soot Particles ◽  
Real Time Detection ◽  
193 Nm

scholarly journals LacI(Ts)-Regulated Expression as an In Situ Intracellular Biomolecular Thermometer

2011 ◽  
Vol 77 (9) ◽  
pp. 2863-2868 ◽  
Author(s):  
K. M. McCabe ◽  
E. J. Lacherndo ◽  
I. Albino-Flores ◽  
E. Sheehan ◽  
M. Hernandez
Keyword(s):  
Real Time ◽  
Heat Content ◽  
Model System ◽  
Temperature Sensitive ◽  
Content Type ◽  
Temperature Changes ◽  
Biologically Relevant ◽  
E Coli ◽  
Heat Transfer Capacity

ABSTRACTIn response to needs forin situthermometry, a temperature-sensitive vector was adapted to report changes in the intracellular heat content ofEscherichia coliin near-real time. This model system utilized vectors expressing increasing quantities of β-galactosidase in response to stepwise temperature increases through a biologically relevant range (22 to 45°C). As judged by calibrated fluorometric and colorimetric reporters, both wholeE. colicells and lysates expressed significant repeatable changes in β-galactosidase activity that were sensitive to temperature changes of less than 1°C (35 to 45°C). This model system suggests that changes in cellular heat content can be detected independently of the medium in which cells are maintained, a feature of particular importance where the medium is heterogeneous or nonaqueous, or otherwise has a low heat transfer capacity. We report here that the intracellular temperature can be reliably obtained in near-real time using reliable fluorescent reporting systems from cellular scales, with a 20°C range of detection and at least 0.7°C sensitivity between 35 and 45°C.

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