Enhancing the speed of morpholino-DNA biosensor by electrokinetic concentration of DNA in a microfluidic chip

Electrochemical nucleic acid biosensors: from fabrication to application

“…[22][23][24][25] The LNA capture probes have been used for simple and specic DNA detection of chronic myeloid leukemia and acute promyelocytic leukemia. [41][42][43][44][45][46] It was reported that the performance of the electrochemical nucleic acid biosensors employing morpholino is comparable to that of their PNA-based counterparts. [29][30][31] Recently, a novel approach to the locking of the furanose ring via a methylene linkage between 4 0 -C and 2 0 -O has been developed.…”

Microfluidic cytometers with integrated on-chip optical systems for red blood cell and platelet counting

“…Figure 5 shows the real FSC signals of 10 lm-diameter particles detected by the detection fibers located at 11 and 13 . As shown in Figure 5, obviously, the FSC signal detected by the detection fiber with 11 deflected angle had a higher background ($3.35 V) and a lower SNR than the FSC signal detected at 13 . Furthermore, the downwards extinction peak in Figure 5(b), which was caused by the particle blocking part of the incident light, was much bigger than that in Figure 5(d).…”

“…On the opposite side of the channel, a detection fiber oriented at a small angle relative to the incident light was applied to detect the FSC signals while, at the same time, avoiding coupling of the direct beam from the light source. When the polystyrene microsphere suspension flowed through the interrogation region at the center of the sample channel sandwiched by sheathing flows, the FSC signals arising from the particles were collected using the detection fiber placed at 13 relative to the incident light and then delivered to the photodetector. Finally, the signals of the photodetector were captured by a data acquisition card (PCI-1710U-DE, Advantech), and data post-processing was carried out using the program written in MATLAB (R2014b, USA).…”

“…Figure 7(c) shows an amplified microscope image of the integrated optical system to illustrate clearly the arrangement of the input fiber, integrated on-chip lens, and the detection fiber around the microfluidic channel. As discussed previously, the detection fiber was placed at 13 relative to the incident light. To confirm the beam waist diameter in the microchannel, the microfluidic channel is filled with Rhodamine B with the concentration of 1 mg/ml to show the property of light spot in the micro channel, accordingly, a 532 nm laser diode was selected as the light source.…”

“…Currently, microchip-based devices have been widely used in clinical blood tests, [6][7][8][9][10] DNA detection, [11][12][13] urine analysis, [14][15][16][17] protein analysis, 18,19 and many other applications. In order to miniaturize the functionality of a conventional flow cytometer, researchers have exerted significant efforts to develop miniaturized flow cytometry devices based on microfluidic chips.…”