scholarly journals Real-Time Monitoring of the In Situ Microfluidic Synthesis of Ag Nanoparticles on Solid Substrate for Reliable SERS Detection

Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 520
Author(s):  
Niccolò Paccotti ◽  
Alessandro Chiadò ◽  
Chiara Novara ◽  
Paola Rivolo ◽  
Daniel Montesi ◽  
...  
Keyword(s):  
Real Time ◽  
Flow Rate ◽  
Ag Nanoparticles ◽  
Morphological Characteristics ◽  
Surface Enhanced Raman Spectroscopy ◽  
Solid Substrate ◽  
Plasmonic Nanostructures ◽  
Rate Variation ◽  
Real Time Monitoring ◽  
Vis Spectroscopy

A sharpened control over the parameters affecting the synthesis of plasmonic nanostructures is often crucial for their application in biosensing, which, if based on surface-enhanced Raman spectroscopy (SERS), requires well-defined optical properties of the substrate. In this work, a method for the microfluidic synthesis of Ag nanoparticles (NPs) on porous silicon (pSi) was developed, focusing on achieving a fine control over the morphological characteristics and spatial distribution of the produced nanostructures to be used as SERS substrates. To this end, a pSi membrane was integrated in a microfluidic chamber in which the silver precursor solution was injected, allowing for the real-time monitoring of the reaction by UV–Vis spectroscopy. The synthesis parameters, such as the concentration of the silver precursor, the temperature, and the flow rate, were varied in order to study their effects on the final silver NPs’ morphology. Variations in the flow rate affected the size distribution of the NPs, whereas both the temperature and the concentration of the silver precursor strongly influenced the rate of the reaction and the particle size. Consistently with the described trends, SERS tests using 4-MBA as a probe showed how the flow rate variation affected the SERS enhancement uniformity, and how the production of larger NPs, as a result of an increase in temperature or of the concentration of the Ag precursor, led to an increased SERS efficiency.

Real-time monitoring of plasmon-induced proton transfer of hypoxanthine in serum

Nanoscale ◽  
2017 ◽  
Vol 9 (34) ◽  
pp. 12307-12310 ◽  
Author(s):  
Binbin Zhou ◽  
Shaofei Li ◽  
Xianghu Tang ◽  
Pan Li ◽  
Xiaomin Cao ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Proton Transfer ◽  
Real Time ◽  
Surface Enhanced Raman Spectroscopy ◽  
Intramolecular Proton Transfer ◽  
Real Time Monitoring ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Intramolecular proton transfer of hypoxanthine, induced by application of a laser on the surface of a bare noble nanomaterial, was monitored in real time using surface-enhanced Raman spectroscopy (SERS).

A Novel Approach of Dynamic Parameter Calculation in Real Time While Managed Pressure Cementing and its application in Ultra-Deep Well

2021 ◽  
Author(s):  
Haobo Zhou ◽  
Guo Wang ◽  
Jinge Liu ◽  
Lianzhong Sun ◽  
Hongning Zhang
Keyword(s):  
Real Time ◽  
Simulation Software ◽  
Hydraulic Calculation ◽  
Rate Variation ◽  
Dynamic Parameters ◽  
Real Time Monitoring ◽  
Deep Well ◽  
Geological Conditions ◽  
Replacement Process ◽  
Parameters Calculation

Abstract Tremendous amounts of oil and gas reservoir are located in ultra-deep formations, such as Shunnan block in Tarim basin of China, some reservoirs buried deeper than 8000m and which are major exploration areas of SINOPEC. The formation geological conditions are complicated, multiple pressure systems co-exist in the same borehole, narrow pressure-margin problems, all above may cause down-hole troublesome conditions while cementing, such as leaking, fracturing formations and so on. And the managed pressure cementing (MPC) was selected for solving the above problems. But the key for a successful MPC depend on accurate, real-time knowledge of dynamic parameters calculation. Therefore, a real time dynamic parameters calculation for MPC is very important. Firstly, a comprehensive real-time hydraulic calculation method for cementing replacement process was established, in which the difference of density, rheological properties, location and length of different fluids were taken into account. In order to improve the calculation precision, the flow channel both in pipe and annuli was divided into several sections, through which the different diameters of the channels were considered. Secondly, according to the density contrast of operating fluids, a vacuum (U-Tube effect) will appear at the inlet in the cementing replacement process, an integrated U-Tube effect analytical model was established based on the Euler equation, in which the influence of well deviation was taken into account too, and though which the height and volume of vacuum, the down-hole operating fluids acceleration, the out flow rate variation et al. all can be accurately calculated and simulated. Moreover, a series of system calculation software were developed to predict cementing fluids position, fluids acceleration, flow pressure drop, BHP, expected WHP and the related control parameters for MPC. The proposed model has been applied in HPHT ultra-deep well MPC operation of SINOPEC Northwest oil filed in Traim basin, there is an excellent match between the calculated and measured data. Furthermore, this simulation software has been used for designing the MPC parameters, and it runs smoothly with convenient operation. Therefore it can be seen this system can be applied to provide more convenient fast and precise dynamic parameters monitoring for MPC. This study proposed a novel model of Cementing dynamic parameters calculating and developed a comprehensive real-time monitoring system for MPC. Through the application of the monitoring, we can adjust the cementing parameters in real time while MPC, and this real-time monitoring has been applied in several wells very well. Therefore, this study is novel and can afford an effective approach to improve cement quality.

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