Effect Of Surface Charge Research Articles

Selective Adsorption of Hazardous Substances from Wastewater by Hierarchical Oxide Composites: A Review.

Large volumes of wastewater containing toxic contaminants (e.g., heavy metal ions, organic dyes, etc.) are produced from industrial processes including electroplating, mining, petroleum exploitation, metal smelting, etc., and proper treatment prior to their discharge is mandatory in order to alleviate the impacts on aquatic ecosystems. Adsorption is one of the most effective and practical methods for removing toxic substances from wastewater due to its simplicity, flexibility, and economics. Recently, hierarchical oxide composites with diverse morphologies at the micro/nanometer scale, and the combination advantages of oxides and composite components have been received wide concern in the field of adsorption due to their multi-level structures, easy functionalization characteristic resulting in their large transport passages, high surface areas, full exposure of active sites, and good stability. This review summarizes the recent progress on their typical preparation methods, mainly including the hydrothermal/solvothermal method, coprecipitation method, template method, polymerization method, etc., in the field of selective adsorption and competitive adsorption of hazardous substances from wastewater. Their formation processes and different selective adsorption mechanisms, mainly including molecular/ion imprinting technology, surface charge effect, hard-soft acid-base theory, synergistic effect, and special functionalization, were critically reviewed. The key to hierarchical oxide composites research in the future is the development of facile, repeatable, efficient, and scale preparation methods and their dynamic adsorption with excellent cyclic regeneration adsorption performance instead of static adsorption for actual wastewater. This review is beneficial to broaden a new horizon for rational design and preparation of hierarchical oxide materials with selective adsorption of hazardous substances for wastewater treatment.

Interfacial Interaction between Functionalization of Polysulfone Membrane Materials and Protein Adsorption.

This study that modified polysulfone membranes with different end-group chemical functionalities were prepared using chemical synthesis methods and experimentally characterized. The molecular dynamics (MD) method were used to discuss the adsorption mechanism of proteins on functionalized modified polysulfone membrane materials from a molecular perspective, revealing the interactions between different functionalized membrane surfaces and protein adsorption. Theoretical analysis combined with basic experiments and MD simulations were used to explore the orientation and spatial conformational changes of protein adsorption at the molecular level. The results show that BSA exhibits different variability and adsorption characteristics on membranes with different functional group modifications. On hydrophobic membrane surfaces, BSA shows the least stable configuration stability, making it prone to nonspecific structural changes. In addition, surface charge effects lead to electrostatic repulsion for BSA and reduce the protein adsorption sites. These MD simulation results are consistent with experimental findings, providing new design ideas and support for modifying blood-compatible membrane materials.

Electromagnetohydrodynamic (EMHD) flow of Jeffrey fluid through a rough circular microchannel with surface charge-dependent slip.

This research examines the electromagnetohydrodynamic (EMHD) flow of Jeffrey fluid in a rough circular microchannel while considering the effect of surface charge on slip. The channel wall corrugations are described as periodic sinusoidal waves with small amplitudes. The perturbation method is employed to derive solutions for velocity and volumetric flow rate, and a combination of three-dimensional (3D) and two-dimensional (2D) graphical representations is utilized to effectively illustrate the impacts of relevant parameters on them. The significance of the Reynolds number in investigations of EMHD flow is particularly emphasized. Furthermore, the effect of wall roughness and wave number on velocity and the influence of wall roughness and surface charge density on volumetric flow rate are primarily focused on, respectively, at various Reynolds numbers. The results suggest that increasing the wall roughness leads to a reduction in velocity at low Reynolds numbers ( ) and an increment at high Reynolds numbers ( ). For any Reynolds number, a roughness with an odd multiple of wave number ( ) will result in a more stable velocity profile compared to one with an even multiple of wave number ( ). Decreasing the relaxation time while increasing the retardation time and Hartmann number can diminish the impact of wall roughness and surface charge density on volumetric flow rate, independent of the Reynolds number. Interestingly, in the existence of wall roughness, further consideration of the effect of surface charge on slip leads to a 15% drop in volumetric flow rate at and a 32% slippage at . However, in the condition where the effect of surface charge on slip is considered, further examination of the presence of wall roughness only results in a 1.4% decline in volumetric flow rate at and a 1.6% rise at . These findings are crucial for optimizing the EMHD flow models in microchannels.

Secondary electron emission reduction from boron nitride composite ceramic surfaces by the artificial microstructures and functional coating

Boron nitride-silicon dioxide (BN–SiO2) composite ceramic is a typical Hall thruster wall material, and its secondary electron emission (SEE) property dominates the sheath characteristics inside the thrusters. Lowering the SEE yield (SEY) of the wall surface can remarkably improve the sheath stability of Hall thrusters. To accomplish the SEY reduction for BN–SiO2, artificial surface microstructure and surface coating technologies are employed. The morphology analysis demonstrated the shape and feature sizes of the microstructure could be largely controlled by adjusting the laser etching parameters. Then we realized an increasingly significant SEY reduction for BN–SiO2 as the average aspect ratio of the microhole increases. The microstructures showed a remarkable SEY reduction when the laser power was 10 W and the scanning cycle was 50. In this case, the SEY peak values (δ m) of the two BN–SiO2 samples with mass ratios of 7:3 and 6:4 decrease from 2.62 and 2.38 to 1.55 and 1.46 respectively. For a further SEY reduction, a sputtering process was employed to deposit TiN film on the microstructures. The results showed that the TiN coating of 246 nm thickness reduced the δ m values of the two samples from 1.55 and 1.46 to 0.82 and 0.76, which achieved a notable SEY reduction compared to the original surface. Via simulation work, the SEY reduction achieved by microstructures was theoretically interpreted. Besides, by considering the effect of surface charging, the results of SEY converged to 1 with the irradiation pulse increasing presented. The research demonstrated a remarkable SEY reduction for BN–SiO2 ceramic by constructing surface microstructure and depositing TiN coating, which has application sense for low SEY engineering in specific working scenarios.

Why Bubbles Coalesce Faster than Droplets: The Effects of Interface Mobility and Surface Charge.

Air bubbles in pure water appear to coalesce much faster compared to oil emulsion droplets at the same water solution conditions. The main factors explaining this difference in coalescence times could be interface mobility and/or pH-dependent surface charge at the water interface. To quantify the relative importance of these effects, we use high-speed imaging to monitor the coalescence of free-rising air bubbles with the water-air interface as well as free-falling fluorocarbon-oil emulsion droplets with a water-oil interface. We measure the coalescence times of such bubbles and droplets over a range of different water pH values (3.0, 5.6, 11.0). In the case of bubbles, a very fast coalescence (milliseconds) is observed for the entire pH range in pure water, consistent with the hydrodynamics of fully mobile interfaces. However, when the water-air interface is immobilized by the deposition of a monolayer of arachidic acid, the coalescence is significantly delayed. Furthermore, the coalescence times increase with increasing pH. In the case of fluorocarbon-oil droplets, the coalescence is always much slower (seconds) and consistent with immobile interface coalescence. The fluorocarbon droplet's coalescence time is also pH-dependent, with a complete stabilization (no coalescence) observed at pH 11. In the high electrolyte concentration, a 0.6 M NaCl water solution, bubbles, and droplets have similar coalescence times, which could be related to the bubble interface immobilization at the late stage of the coalescence process. Numerical simulations are used to evaluate the time scale of mobile and immobile interface film drainage.

Peculiarities in XPS spectra of Sn/SiO2 layers as an effect of surface charge

X-ray photoelectron spectroscopy based on synchrotron radiation was used to investigate the composition of the observed SnO2-x/Sn:SiO2-x thin layer grown by organometallic chemical vapour deposition on single-crystalline silicon wafer with additional argon ions etching treatment. Due to the formation of a thermodynamic anomaly during in situ layer growth, an efficient oxygen exchange between silicon and tin oxide phases occurs. The present study addresses the effect of localized surface charging and its influence on the obtained XPS core level spectra. We found that due to the high electrical conductivity of metallic tin and the direct coupling of tin particles to the silicon wafer, the XPS Sn 3d5/2 core level spectrum is not affected by the surface charge compared to the highly charged dielectric silicon oxide matrix, as observed for the XPS O 1 s and Si 2p core level spectra. Our results show that the core level spectra of Si 2p and O 1 s are shifted up to 3 eV due to the presence of uncompensated positive charge on the surface of the silica matrix. These results provide insight into the influence of surface charge effects on the analysis of conductor/insulator composite materials and contribute to the application of Sn-based materials in various application concepts related to energy and surface functionalization.

Harnessing bio-based chelating agents for sustainable synthesis of AgNPs: Evaluating their inherent attributes and antimicrobial potency in conjunction with honey

Greenly synthesized nanoparticles have garnered attention due to their low environmental footprint, but impurities limit their applications. A novel semi-organic method for synthesizing silver nanoparticles (AgNPs) using bio-based chelating fuels (Beta vulgaris subsp., Spinacia oleracea, and Ipomoea batatas) reduces the undesirable impurities. The study also showcases the impact of bio-based chelating fuel on various characteristics of AgNPs in comparison to synthetic chelating fuel. The antimicrobial efficacy of the synthesized AgNPs in conjunction with honey was also assessed against E. coli. The XRD analysis showed cubic structure of AgNPs. The FESEM and TEM analysis showed that the well-connected spherical-shaped AgNPs (∼3–120 nm diameter) while EDS confirmed the presence of Ag in all samples. The TEM analysis also revealed layers of carbonates in AgNPs synthesized using bio-based chelating fuels. XPS investigation confirmed the absence of any prominent impurities in prepared samples and AgNPs have not experienced oxidation on their surface. However, notable surface charging effects due to the uneven conductivity of the particles were observed. The broth dilution method showed that all mixtures containing AgNPs in combination with honey exhibited a significant bacterial growth reduction over a period of 120 h. The highest growth reduction of ∼75 % is obtained for the mixture having AgNPs (Ipomoea batatas) while the least growth reduction of ∼51 % is obtained for the mixture having AgNPs (Beta vulgaris subsp.). The findings affirm that AgNPs can be successfully synthesized using bio-based chelating fuels with negligible ecological consequences and devoid of contaminants. Moreover, the synthesized AgNPs can be employed in conjunction with honey for antibacterial purposes.

Revealing the Regulation Effect of Surface Charge at Aromatic Interface to Dynamic Conformational Changes of α‐Synuclein at Early Aggregation Stage

Comprehensive SummaryThe aggregation of α‐synuclein (α‐syn) is strongly influenced by membrane interfaces, but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear. Here, we investigate the adsorption and structure changes of α‐syn on oppositely charged aromatic interfaces through in‐situ surface‐enhanced infrared absorption (SEIRA) spectroscopy and nano‐IR technique. The results show that the synergy of electrostatic and hydrophobic interactions leads to a “fast‐slow” two‐step aggregation pathway on negatively charged interface. Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region, which enables the hydrophobic stacking between nearby NAC regions. Stable antiparallel β‐sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed “first layer”. Monomers electrostatically adsorb on positively charged interface by C‐terminus with NAC region and N‐terminus stretched in solvent, which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C‐terminus exposure. Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways, which provide insights into dynamic conformation changes of α‐syn at early aggregation stage and imply the important role of spatial‐temporal heterogeneity of membranes in α‐synucleinopathies.

Effect of particle size versus surface charge on the brain targeting behavior of elastic nanovesicles: In-vitro characterization, comparison between I-optimal and D-optimal statistical optimization and in-vivo pharmacokinetic evaluation

Rasagiline mesylate (RM) is a potent monoamine oxidase-B inhibitor that suffers from extensive hepatic metabolism, low bioavailability, and low brain distribution. Thus, this study aimed to formulate an intranasal nanovesicular system with high RM encapsulation (EE%) and enhanced delivery to the brain tissues. In this perspective, negatively and positively charged RM-transfersomal vesicles were prepared, characterized and the formulation parameters were statistically optimized as per two different response surface methodologies namely, I-optimal and D-optimal design. Although both statistical designs acted almost similarly in terms of experimental response analysis; the I-optimal design might be functioning better in terms of formulations’ optimization and response prediction with higher desirability factors. Consequently, the optimized negative transfersomes (particle size: 213 nm, EE%:62.55 %) and positive transfersomes (particle size: 515 nm, EE%:70.9 %) suggested by the I-optimal design were furtherly formulated, characterized for their in-vitro release, elasticity, transmission electron microscope and pH. Finally, both systems were administered intranasally and compared to an intravenous RM solution where the optimized positive transfersomes has shown significantly higher brain targeting efficiency, positive direct transfer percentage values and longer brain mean residence time. These results suggested that the surface charge of the formulated vesicles could be more effective factor -than the particle size-in enhancing the brain bioavailability of the administered drugs.

Immunogenic and toxic effects of graphene oxide nanoparticles in mouse skeletal muscles and human red blood cells

To investigate immunogenic and toxic effects of graphene oxide (GO) nanoparticles in mouse skeletal muscles and in human blood in vitro. GO nanoparticles prepared using a probe sonicator were supended in deionized H2O or PBS, and particle size and surface charge of the nanoparticles were measured with dynamic light scattering (DLS). Different concentrations (0.5, 1.0 and 2.0 mg/mL) of GO suspension or PBS were injected at multiple sites in the gastrocnemius muscle (GN) of C57BL/6 mice, and inflammatory response and immune cell infiltrations were detected with HE and immunofluorescence staining. We also examined the effects of GO nanoparticles on human red blood cell (RBC) morphology, hemolysis and blood coagulation using scanning electron microscope (SEM), spectrophotometry, and thromboelastography (TEG). GO nanoparticles suspended in PBS exhibited better colloidal dispersity, stability and surface charge effects than those in deionized H2O. In mouse GNs, injection of GO suspensions dose- and time-dependently resulted in sustained muscular inflammation and myofiber degeneration at the injection sites, which lasted till 8 weeks after the injection; immunofluorescence staining revealed obvious infiltration of monocytes, macrophages, dendritic cells and CD4+ T cells around the injection sites in mouse GNs. In human RBCs, incubation with GO suspensions at 0.2, 2.0 and 20 mg/mL, but not at 0.002 or 0.02 mg/mL, caused significant alterations of cell morphology and hemolysis. TEG analysis showed significant abnormalities of blood coagulation parameters following treatment with high concentrations of GO. GO nanoparticles can induce sustained inflammatory and immunological responses in mouse GNs and cause RBC hemolysis and blood coagulation impairment, suggesting its muscular toxicity and hematotoxicity at high concentrations.

Surface Charge Effects for the Hydrogen Evolution Reaction on Pt(111) Using a Modified Grand-Canonical Potential Kinetics Method.

Surface charges of catalysts have important influences on the thermodynamics and kinetics of electrochemical reactions. Herein, we develop a modified version of the grand-canonical potential kinetics (GCP-K) method based on density functional theory (DFT) calculations to explore the effect of surface charges on reaction thermodynamics and kinetics. Using the hydrogen evolution reaction (HER) on the Pt(111) surface as an example, we show how to track the change of surface charge in a reaction and how to analyze its influence on the kinetics. Grand-canonical calculations demonstrate that the optimum hydrogen adsorption energy on Pt under the standard hydrogen electrode condition (SHE) is around -0.2 eV, rather than 0 eV established under the canonical ensemble, due to the high density of surface negative charges. By separating the surface charges that can freely exchange with the external electron reservoir, we obtain a Tafel barrier that is in good agreement with the experimental result. During the Tafel reaction, the net electron inflow into the catalyst leads to a stabilization of canonical energy and a destabilization of the charge-dependent grand-canonical component. This study provides a practical method for obtaining accurate grand-canonical reaction energetics and analyzing the surface charge induced changes.

Calcium carbonate formation mechanism in MSHC revealed by molecular simulation

ABSTRACT Microbial self-healing concrete (MSHC) is an eco-friendly material that supports low-carbon development. However, the formation mechanism of calcium carbonate (CaCO3) in MSHC remains unclear. This study investigated the formation process of CaCO3 clusters in MSHC using molecular simulation. The hydroxide ion and carbonate ion (CO3 2−) would compete for association with calcium ion in MSHC. The formation process of CaCO3 clusters could be summarised as follows: free ions first associated to form ion pairs, then ion pairs aggregated into small clusters through ion-dipole interactions, and finally, small clusters overcame the surface charge effect by high-frequency aggregation-separation behaviour to transform into large clusters and further densify themselves. The reaction rate of CaCO3 cluster formation decreased significantly with the decrease of CO3 2− concentration, and the association between calcium ion and hydroxide ion would dominate when the CO3 2− concentration was low.

Bridging Ionic Current Rectification and Resistive-Pulse Sensing for Reliable Wide-Linearity Detection.

As two mainstream ionic detection techniques, ionic current rectification (ICR) suffers from large fluctuations in trace level detection, while resistive-pulse sensing (RPS) encounters easy clogs in high-concentration detection. By rationally matching the nanopore size with the DNA tetrahedron (TDN), this work bridges the two techniques to achieve reliable detection with wide linearity. As a representative analyte, miRNA-10b could specifically combine with and release TDN from the interior wall, which thus induced the simultaneous generation of distinct ICR and RPS signals. The ICR signals could be attributed to the balance between the effective orifice and surface charge density of the inner wall, while the RPS signals were induced by the complex of miRNA-10b and TDN passing through the nanopore. Such an operation contributed to a wide detection range of 1 fM-1 nM with a good linearity. The feasibility of this method is also validated in single-cell and real plasma detection.

Zirconium-based metal–organic frameworks/porous carbon hybrids as high-performance anode materials for highly stable lithium- and potassium-ion batteries

Metal-organic framework (MOF)-derived carbon materials have been widely investigated as advanced electrode materials. However, post-synthetic modifications suffer from certain limitations in morphology, surface area, and pore size control. Herein, we report a simple strategy to synthesize surface-confined Zirconium(Zr)-based MOF UiO-66-NH2 carbon hybrids (Zr-MOF@C; denoted as Zr-MOF, Zr-MOF@C10, Zr-MOF@C25, and Zr-MOF@C50) through a covalent assembly/amide linkage between the MOFs and hierarchical porous carbon (PC) in various proportions under solvothermal conditions. Zr-MOF@C hybrids have been utilized as the anode materials for lithium- (LIBs) and potassium-ion batteries (KIBs). In LIBs, the Zr-MOF@C10, Zr-MOF@C25 and Zr-MOF@C50 anodes delivered the discharge capacities of 126, 65 and 94 mA h g−1 at 100 mA g−1 after 100 cycles, respectively. In KIBs, the Zr-MOF@C10 and Zr-MOF@C25 exhibited the high discharge capacities of 78 and 70 mA h g−1 at 100 mA g−1 over 100 cycles. In addition, the Zr-MOF@C25 and Zr-MOF@C50 anodes exhibited an outstanding rate capability with a reversible capacity of ∼166 mA h g–1 vs. K/K+ and 176 mA h g–1 for Li/Li+, respectively, while well-maintained long-term cyclic stabilities of ∼57 mA h g–1 (Zr-MOF@C25 vs. K/K+) and ∼140 mA h g–1 (Zr-MOF@C50 vs. Li/Li+) at 1 A g–1 over 1000 cycles. The electrochemical kinetics studies revealed that Li+ and K+ storage efficiencies of all anodes were dominated by a surface-charge capacitive effect and diffusion-driven charge storage mechanism, respectively. These findings provide new insights for designing high-performance surface-confined MOF-based carbon composite materials for next-generation high-energy storage devices.

Controllable Synthesis of Porous and Hollow Nanostructured Catalyst Particles and Their Soot Oxidation.

The introduction of macroporous structures into three-way catalysts (TWCs) through polymer template-assisted spray drying has attracted attention because of its enhanced gas diffusion and catalytic performance. However, the surface charge effect of polymeric template components has not been investigated to control the structure of the TWC particles during synthesis. Thus, this study investigated the effect of template surface charges on the self-assembly behavior of TWC nanoparticles (NPs) during drying. The self-assembly of TWC NPs and polymer particles with different charges produced a hollow structure, whereas using the same charges generated a porous one. Consequently, the mechanism of particle self-assembly during drying and final structure particle formation is proposed in this study. Here, porous TWC particles demonstrated a faster oxidation of soot particles than that of hollow-structured particles. This occurred as a result of the larger contact area between the catalyst surface and the solid reactant. Our findings propose a fundamental self-assembly mechanism for the formation of different TWC structures, thereby enhancing soot oxidation performance using macroporous structures.

Surface Charge: An Advantage for the Piezoelectric Properties of GaN Nanowires

The optimization of the new generation of piezoelectric nanogenerators based on 1D nanostructures requires a fundamental understanding of the different physical mechanisms at play, especially those that become predominant at the nanoscale regime. One such phenomenon is the surface charge effect (SCE), which is very pronounced in GaN NWs with sub-100 nm diameters. With an advanced nano-characterization tool derived from AFM, the influence of SCE on the piezo generation capacity of GaN NWs is investigated by modifying their immediate environment. As-grown GaN NWs are analysed and compared to their post-treated counterparts featuring an Al2O3 shell. We establish that the output voltages systematically decrease by the Al2O3 shell. This phenomenon is directly related to the decrease of the surface trap density in the presence of Al2O3 and the corresponding reduction of the surface Fermi level pinning. This leads to a stronger screening of the piezoelectric charges by the free carriers. These experimental results demonstrate and confirm that the piezo-conversion capacity of GaN NWs is favoured by the presence of the surface charges.

Conical Structures on the Liquid Surface in an Electric Field: Effect of Volume and Surface Charges

Conical Structures on the Liquid Surface in an Electric Field: Effect of Volume and Surface Charges

Enhanced Rectification Performance in Bipolar Janus Graphene Oxide Channels by Lateral Electric Fields.

Improving the ionic rectification in nanochannels enables versatile applications such as biosensors, energy harvesting, and fluidic diodes. While previous work mostly focused on the effect of channel geometry and surface charge, in this work via a series of molecular dynamics simulations, we find a striking phenomenon that the ionic current rectification (ICR) ratio in Janus graphene oxide (GO) channels can be tremendously promoted by lateral electric fields. First, under a given axial electric field, an additional lateral electric field can improve the ICR ratio by several times to an order, depending on the channel symmetry. The symmetric channel has an obviously greater ICR ratio because it maintains a more pronounced ion transport disparity at opposite axial fields. The underlying mechanism for the function of the lateral electric field is that it promotes the lateral migration of ions and thus amplifies the ion-residue electrostatic interaction at opposite axial fields, enlarging the ion dynamical difference. Furthermore, for different axial electric fields, the ICR ratio can always be improved by lateral electric fields (up to two orders), suggesting that the ICR improvement is universal. Our results demonstrate that applying a lateral electric field could be a new method to improve the rectification performance of nanochannels, providing valuable guidance for the design of efficient ionic diode devices.

Preparation and characterization of aspirin–fucoidan complex and its admirable antitumor activity on human non-small cell lung cancer cells

The purpose of this work is to prepare a novel acetylated derivative of Undaria pinnatifida fucoidan (UPFUC) with admirable antitumor activity. Fucoidan was first acetylated by acetylsalicylic acid (aspirin, ASA) to form the ASA-UPFUC complex. The antitumor efficacy results stated that ASA-UPFUC inhibited the proliferation of human non-small cell lung cancer A549 cells in a dose-dependent manner, with an IC50 value of 49.09 μg/mL, 50.20 % lower than that of UPFUC. Importantly, the acetylation process had no adverse effects on the backbone structure of UPFUC. Simultaneously, ASA-UPFUC demonstrated a larger charge density than UPFUC, leading to enhanced solubility, improved surface charge effects, and a greater potential for exerting biological activity. Consequently, ASA-UPFUC increased the formation of alkyl and hydrogen bonds with tumor necrosis factor related apoptosis-inducing ligand receptors DR4 and DR5, thereby effectively stimulating the generation of cellular reactive oxygen species, diminishing mitochondrial membrane potential, suppressing nuclear factor κB (NFκB) p65 phosphorylation, enhancing the contents of Bax and cleaved caspase 3, and reducing the level of Bcl-2. The collective effects ultimately triggered the mitochondrial apoptotic pathway, leading to apoptosis in A549 cells. The findings support the potential utilization of ASA-UPFUC as a novel dietary additive for human lung cancer chemoprevention.

One-step fabricating a PDMS optical lens based on surface charging and edge pining effects of a PDMS droplet

This paper presents a one-step method for fabricating a PDMS optical lens based on the surface charging and edge pining effects of a PDMS droplet. This method works by electrically lifting the air-liquid PDMS interface initially stabilized by the edge pining effect of a PDMS droplet on a polymethyl methacrylate (PMMA) substrate. The electrical lifting was achieved under the force interaction between the negative surface charges of the PDMS droplet and the non-uniform electric field generated by a needle-plate electrode pair. Experimental results show that the electrical lifting was achieved in about 10 seconds. With the increase of the applied electric field, the magnification of the fabricated lens increases. Fabricating a lens with a resolution of 32 lp/mm and a magnification of 23.92 times was obtained under an averaged electric field of 12500 V/cm. Chlorophyll-fluorescence-based living algae detection with the PDMS lens and a smartphone imaging system was successfully achieved.