Recent advances in heterogeneous micro-photoreactors for wastewater treatment application

Micro-photoreactor is a miniaturized photoreactor that integrates the advantages of microfluidics into a conventional photoreactor. Miniaturized photoreactors for wastewater treatment require relatively small quantities of photocatalyst material (femtolitre to nanolitre) and provide unique features such as high surface to volume ratio, better control of reaction parameters and efficient heat and mass transfer. The thin layer of photocatalyst in the microreactor, allows less photon loss and uniform light distribution, making it suitable for photocatalytic wastewater treatment applications. The focus of this review is the recent advancement in the area of microfluidic reactors for heterogeneous photocatalysis with details of reactor design principles, typical reactor configurations, reactor fabrication protocols, choice of reactor material and effect of process parameters such as flow rate, concentrations, light intensity, channel length on the photocatalytic reaction. We also discuss how the limitations faced by conventional photoreactors are addressed by micro-photoreactors in the context of wastewater treatment

Current commercial dPCR platforms: technology and market review

Digital polymerase chain reaction (dPCR) technology has provided a new technique for molecular diagnostics, with superior advantages, such as higher sensitivity, precision, and specificity over quantitative real-time PCRs (qPCR). Eight companies have offered commercial dPCR instruments: Fluidigm Corporation, Bio-Rad, RainDance Technologies, Life Technologies, Qiagen, JN MedSys Clarity, Optolane, and Stilla Technologies Naica. This paper discusses the working principle of each offered dPCR device and compares the associated: technical aspects, usability, costs, and current applications of each dPCR device. Lastly, up-and-coming dPCR technologies are also presented, as anticipation of how the dPCR device landscape may likely morph in the next few years. © 2022 Informa UK Limited, trading as Taylor & Francis Group

Fig 4 -

PCR amplification curve (a) for the positive internal specificity check with Ldna (lambda DNA) in the green channel using HEX for singleplex and multiplex assays (b) for the predetermined concentration of 16s marker in the blue channel using FAM at different concentration of Ldna and (c) for different prime and probe concentration at 10 pg Ldna concentrations for both HEX and FAM.</p

S4 Fig -

Specificity check for cross reaction and contamination (a) FAM (b) TEXAS (c) CY5 (d) HEX and (e) Candida. Specificity check for the multiplex assay. (DOCX)</p

Fig 1 -

Schematic of the developed protocol to identify MRSA from whole blood showing: (a) the addition of equal volumes of spiked blood and buffer to which magnetic beads are added (b) the mmixture of spiked blood and ApOH-coated magnetic beads is placed onto a thermomixer maintained at 37ºC, 1000 RPM for 30 mins (c) The mixture is placed on a magnetic stand for 10 mins where the beads with the bacteri magnetic beads-bacteria complex are laterally pelleted (d) the magnetic beads-bacteria complex are lysed using the in-house sonicator horn (e) the clean lysate is added to the PCR reagents on which RT-PCR is performed.</p

S1 Raw images -

Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide range of hospital and community-acquired infections worldwide. MRSA is associated with worse clinical outcomes that can lead to multiple organ failure, septic shock, and death, making timely diagnosis of MRSA infections very crucial. In the present work, we develop a method that enables the positive enrichment of bacteria from spiked whole blood using protein coated magnetic beads, followed by their lysis, and detection by a real-time multiplex PCR directly. The assay targeted bacterial 16S rRNA, S. aureus (spa) and methicillin resistance (mecA). In addition, an internal control (lambda phage) was added to determine the assay’s true negative. To validate this assay, staphylococcal and non-staphylococcal bacterial strains were used. The three-markers used in this study were detected as expected by monomicrobial and poly-microbial models of the S. aureus and coagulase-negative staphylococci (CoNS). The thermal cycling completed within 30 mins, delivering 100% specificity. The detection LoD of the pre-processing step was ∼ 1 CFU/mL from 2-5mL of whole blood and that of PCR was ∼ 1pg of NA. However, the combined protocol led to a lower detection limit of 100–1000 MRSA CFUs/mL. The main issue with the method developed is in the pre-processing of blood which will be the subject of our future study.</div

PCR Amplification curve for 16s marker: Singleplex FAM.

PCR Amplification curve for 16s marker: Singleplex FAM.</p

Primer-probe sets used in this study and their target amplification sequences.

Primer-probe sets used in this study and their target amplification sequences.</p

Fig 3 -

(a), (c) and (e) show the PCR linearity curves and (b), (d) and (f) show the PCR amplification curves for (a) and (b) spa marker in the red channel using TEXAS, (c) and (d) mecA marker in the pink channel using CY5 and (e) and (f) 16s marker in the blue channel using FAM. All linearity curves shows 90% PCR efficiency and good linearity with R2 ∼ 0.99 while the amplification curves showed sigmoidal.</p

The <i>C</i>_<i>q</i> and standard deviations (SD) for full protocol on whole blood spiked with SA of varying initial concentrations.

The Cq and standard deviations (SD) for full protocol on whole blood spiked with SA of varying initial concentrations.</p