In this work, an efficient method for the sequence-specific detection of DNA based on a morpholino-functionalized silicon chip platform has been proposed. Briefly, morpholino was first immobilized on the surface of a silicon chip using 3-aminopropyltriethoxysilane (APTES) as the silane coupling agent and 1,4-phenylenediisothiocyanate (PDITC) as the cross-linker and then hybridized with DNA in the ensuing step. The fluorescence label was introduced by strongly binding Rhodamine B, which contains a terminal carboxylic group, with DNA by means of phosphate–zirconium–carboxylate coordination reaction. X-ray photoelectron spectroscopy (XPS) was used to characterize the silicon surface. Under optimal conditions, the morpholino-functionalized silicon chip presented a great linear relationship between the fluorescence intensity and the logarithm of target DNA concentrations in the range from 1 pM to 1 nM with a detection limit of 4.52 pM. Furthermore, fully complementary versus single-base mismatched, three-base mismatched and non-complementary DNA could be effectively identified. The chip showed excellent stability because it could be reused for another hybridization experiment after denaturing the morpholino–complementary DNA duplex. In addition, the chip rendered satisfactory analytical performance for the detection of DNA in serum samples, thus exhibiting practical significance. Morpholino-functionalized silicon chips display good sensitivity and selectivity for the detection of DNA and promising applications in single-nucleotide polymorphisms (SNPs).
Hongqiang Chen,Xiang Ma,Yonghai Zhang,Jinjia Wei,Paolo Di Marco
Enhancing flow boiling in microchannel via surface modification is crucial for addressing the energy consumption challenges posed by high-power compact electronic devices. However, improving boiling heat transfer performance with well-defined nanostructured surfaces in a limited space remains a challenge. Herein, we present a simple and straightforward acoustofluidics strategy for stable, controllable, and efficient fabricates of functional Zinc oxide (ZnO) nanoarray silicon chip surface with excellent phase change cooling performance. The intentionally designed flower-like sharp-edge structure integrated acoustic has been experimentally and numerically verified for its enhanced mass transfer mixing. The resulting ZnO nanoarray-coated chip with customizable lengths, densities, and morphology is implemented by simple reactor parameter adjustment. Excellent boiling heat transfer performance is obtained on this surface, giving priority to nucleation (superheat≈ 4 °C), low energy consumption (≤3.2 kPa) and simultaneously enhancing the critical heat flux (CHF) and heat-transfer coefficient (HTC) by up to 70.8 % and 107.5 %, respectively, compared with a smooth chip surface. In situ observation and analysis of the wicking of the nanoarray and nucleation, growth, and departure of the bubbles reflect that ZnO nanoarray promotes the phase change heat exchange process by the large number of nucleation sites and ultrafast liquid re-wetting. These findings not only provide important guidelines for the precise control and rational design of functional nanomaterials , but also provide new insights for embedded cooling and significant energy savings on power devices.