Colloidal AgNPs Research Articles

Rapid Microwave-Assisted Synthesis of Silver Nanoparticles in a Halide-Free Deep Eutectic Solvent

Organosoluble silver nanoparticles (AgNPs) have been synthesized for the first time in a task-specific, halide-free, deep eutectic solvent (DES) using a simple and convenient wet chemical reduction route involving microwave (MW) heating with oleylamine (OAm) acting as a surfactant and reducing agent. Nanoparticle formation is extremely rapid and occurs within 30 s of microwave heating at 100 °C. The effects of various reaction parameters (e.g., synthesis temperature, MW irradiation time, maximal MW power, water content of the medium) on the size and uniformity of the prepared AgNPs have been elucidated in this study. The produced colloidal AgNPs were characterized using UV–vis spectroscopy and transmission electron microscopy (TEM), with the aim of identifying reaction parameters simultaneously achieving optimal particle yield and colloid uniformity. This work illustrates how the versatile nature of DESs can be exploited to create unconventional DESs designed for nanoscale tasks for which conventional (e....

Light emitting diode irradiation induced shape conversion of DNA-capped silver nanoparticles and their antioxidant and antibacterial activities

Due to size- and shape-dependent properties, a shape-controlled synthesis of silver nanoparticles (AgNPs) is one of the research challenging topics for their production and potential applications. This work reported the simple eco-friendly syntheses of different shaped AgNPs controlled by the plasmid DNA content and light emitting diodes (LEDs) irradiation. The synthesized AgNPs appeared as yellow, orange and green colloidal AgNPs, which transmission electron microscope (TEM) images revealed their different shapes; spherical AgNPs, a mixture of spherical and hexagonal AgNPs, and a mixture of spherical, hexagonal and corner-truncated triangle AgNPs, respectively. The average sizes of spherical, hexagonal and corner-truncated triangle AgNPs in the green colloidal solution were 12.32 ± 2.22, 23.03 ± 6.62 and 15.84 ± 4.31 nm, respectively. The analyses of X-ray diffraction, selected area electron diffraction and high-resolution TEM indicated the crystalline nature of the synthesized particles as the face-centred cubic silver. All synthesized AgNPs exhibited antioxidant activities similarly, whereas the yellow colloidal AgNPs exhibited the strongest antibacterial activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus as compared with the green and orange colloidal AgNPs.

Antimicrobial Activity of a Colloidal AgNP Suspension Demonstrated In Vitro against Monoculture Biofilms: Toward a Novel Tooth Disinfectant for Treating Dental Caries.

A novel silver nanoparticle (AgNP) formulation was developed as a targeted application for the disinfection of carious dentine. Silver nitrate (AgNO3) was chemically reduced using sodium borohydrate (NaBH4) in the presence of sodium dodecyl sulfate (SDS) to form micelle aggregate structures containing monodisperse 6.7- to 9.2-nm stabilized AgNPs. AgNPs were characterized by measurement of electrical conductivity and dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and inductively coupled plasma mass spectrometry. Antimicrobial activity of AgNPs was tested against planktonic cultures of representative gram-positive and gram-negative oral bacteria using well diffusion assays on tryptic soy broth media and monoculture biofilms grown with brain heart infusion ± sucrose anaerobically at 37°C on microtiter plates. Biofilm mass was measured by crystal violet assay. Effects were compared to silver diamine fluoride and chlorhexidine (negative controls) and 70% isopropanol (positive control) exposed cultures. In the presence of AgNPs, triplicate testing against Streptococcus gordonii DL1, C219, G102, and ATCC10558 strains; Streptococcus mutans UA159; Streptococcus mitis I18; and Enterococcus faecalis JH22 for planktonic bacteria, the minimum inhibitory concentrations were as low as 7.6 µg mL-1 and the minimum bacteriocidal concentrations as low as 19.2 µg mL-1 silver concentration. Microplate readings detecting crystal violet light absorption at 590 nm showed statistically significant differences between AgNP-exposed biofilms and where no antimicrobial agents were used. The presence of sucrose did not influence the sensitivity of any of the bacteria. By preventing in vitro biofilm formation for several Streptococcus spp. and E. faecalis, this AgNP formulation demonstrates potential for clinical application inhibiting biofilms.

Comparative Photocatalytic Degradation of Organic Dyes Using Silver Nanoparticles Synthesized from Padina tetrastromatica

Background: Seaweeds, being abundant sources of active components have attained much interest in recent times. The seaweeds are routinely used in life science research and are well known for their biological applications. In addition to that, the synthesis of metallic nanoparticles from these natural resources has its own attraction in drug delivery and was observed by using 2 mL of Ag NP colloids. Objective: In this study, the synthesis of silver nanoparticles (Ag NPs) using Padina tetrastromatica has been evaluated for their catalytic activity in the degradation of organic dye. Method: The catalytic activity of the biosynthesized Ag NP colloid was studied for the degradation of Methylene blue (MB) and Acridine orange (AO) dye. The degradation of methylene blue and acridine orange was observed at regular time interval by using UV-vis absorption spectra at 664 nm and 490 nm respectively. Results: The percentage of dye degradation increased in the presence of NaBH4. It was observed that 80.09% of MB dye reduction was observed by using 2 mL of Ag NP colloids. The acridine orange dye showed reduction of 83.06%. The rate constants for the reduction of Methylene blue (MB) and acridine orange (AO) dye using 2 mL Ag NPs colloids are 0.077 and 0.090 min-1, respectively.

Applications of Plant Flavonoids in the Green Synthesis of Colloidal Silver Nanoparticles and Impacts on Human Health

Green chemistry is the design of chemical products and processes that eliminate the generation of hazardous substances. In the last few years, natural products especially plant secondary metabolites have been extensively explored for their efficacy to synthesize the silver nanoparticle (AgNPs). The plant-based AgNPs are less hazardous, eco-friendly, energy efficient and safer as compared to chemically synthesized counterparts. Secondary metabolites are significantly found in plants, especially plant flavonoids which have significant role in the synthesis of AgNPs. The flavonoids-based AgNPs have attained much attention in the last few years. The current review presents the potency of flavonoids in the biosynthesis of AgNPs, as reducing and capping agent for the development of uniform size and shape AgNPs. An emphasis on the important role of FTIR in the identification of major functional groups in flavonoids for AgNPs synthesis has been reviewed. AgNPs have wide range of industrial, medical and agricultural applications and also have potential risk to human health. It was found that no such article is available that has discussed the role of plant flavonoids in the green synthesis of colloidal AgNPs.

Structure elucidation and degradation kinetic study of Ofloxacin using surface enhanced Raman spectroscopy

A simple, fast and sensitive surface enhanced Raman spectroscopy (SERS) method for quantitative determination of fluoroquinolone antibiotic Ofloxacin (OFX) is presented. Also the stability behavior of OFX was investigated by monitoring the SERS spectra of OFX after various degradation processes. Acidic, basic and oxidative force degradation processes were applied at different time intervals. The forced degradation conditions were conducted and followed using SERS method utilizing silver nanoparticles (Ag NPs) as a SERS substrate. The Ag NPs colloids were prepared by reduction of silver nitrate using polyethyelene glycol (PEG) as a reducing and stabilizing agent. Validation tests were done in accordance with International Conference on Harmonization (ICH) guidelines. The calibration curve with a correlation coefficient (R=0.9992) was constructed as a relationship between the concentration range of OFX (100–500ng/ml) and SERS intensity at 1394cm−1 band. LOD and LOQ values were calculated and found to be 23.5ng/ml and 72.6ng/ml, respectively. The developed method was applied successfully for quantitation of OFX in different pharmaceutical dosage forms. Kinetic parameters were calculated including rate constant of the degradation of the studied antibiotic.

Investigation on the Effect of Addition of Fe<sup>3+</sup> Ion into the Colloidal AgNPs in PVA Solution and Understanding Its Reaction Mechanism

Analysis of Fe3+ ion present in aqueous solutions is always of interests. Recently, this ion has been analyzed by colorimetric methods using colloid of silver nanoparticles (AgNPs) in capping agents of polymers. The reaction mechanism between AgNPs and Fe3+ is still subject to the further investigation. In this work, 1,10-phenanthroline was used to probe the reaction mechanism between AgNPs and Fe3+ ion in the solution. The colloids of AgNPs were prepared in the polyvinyl alcohol (PVA) solution and reacted with Fe3+. The colloid surface plasmon absorbance decreases linearly along with the increase in Fe3+ concentration. The addition of 1,10-phenanthroline to mixture changes the solution to red, indicating that the reaction produces Fe2+. This suggests that the reduction of the AgNPs absorbance is the result of oxidation of the Ag nanoparticles along with the reduction of Fe3+.

Free energy, configurational and nonextensivity of Tsallis entropy with the size and temperature in colloidal silver nanoparticles in [EMim][PF6] ionic liquid

Molecular dynamic simulation was performed to calculate the configurational entropy and the free energy for colloidal silver nanoparticles (Ag NPs) in 1-Ethyl-3-methylimidazolium Hexafluorophosphate [EMim][PF6] ionic liquid (IL). Furthermore, the density functional theory (DFT) was used to get the potential interaction between the metal surface and ion in IL. The effect of size and temperature on the configurational entropy and the free energy of colloidal Ag NPs were investigated. Then, it was compared with the gas phase. The Tsallis nonextensivity of entropy was investigated for different sizes of colloidal Ag NPs and it was shown that sub-extensivity of entropy occurs for colloidal Ag NPs. In small sizes of colloidal Ag NPs and at low temperature, Tsallis nonextensivity of entropy is important. The pattern of configurational entropy for Ag NPs in terms of size in gas phase is completely different with colloidal Ag NPs in [EMim][PF6] IL solvent. A non-monotonic behavior for the configurational entropy of colloidal Ag NPs in terms of size was observed. The free energy value for Ag NPs in IL increased in proportion with their sizes however, the free energy of Ag NPs in gas phase decreased as Ag NPs size increased. The results regarding the heat capacity of pure IL and the entropy of silver in bulk structure were in line with the available experimental data.

Electrical Conductivity of Methylimidazolium Hexafluorophosphate Ionic Liquid in the Presence of Colloidal Silver Nano Particles with Different Sizes and Temperatures

Colloidal nanoparticle could be used for recognition location of tumors and cancer tissue. A simulation of molecular dynamic for colloidal silver nanoparticles (Ag NPs) based on density functional theory (DFT) potential parametrization with different sizes in 1-ethyl-3-methylimidazolium hexafluorophosphate [EMim][PF6] ionic liquid was performed. Then, using Green Kubo formalism, diffusion coefficient for Ag NPs in IL and in the gas phase was calculated. We also calculated diffusion coefficients of anions and cations for pure IL and IL in the presence of different sizes of Ag NPs at different temperatures. The findings showed that the diffusion coefficient of anions and cations increases in proportion with temperature and the sizes of colloidal Ag NPs. Next, cationic transference number for pure IL and IL in the presence of Ag NPs, electrical conductivity of pure IL, and IL with different sizes of Ag NPs were calculated and compared. After that, the calculated diffusion coefficient and electrical conductiv...

Broad-spectrum antimicrobial activity of bacterial cellulose silver nanocomposites with sustained release

Bacterial cellulose-based antifouling materials have been produced by incorporation of silver nanoparticles for broad-spectrum antimicrobial activity. Three variations of silver nitrate (AgNO3) to reducing agent concentrations have been tried to vary the silver nanoparticle dimension. The formation of silver nanoparticles was also evidenced by the X-ray diffraction, and the crystallite size was found to decrease with increase in NaBH4 concentration. AgBC composites having < 2% (W/W) of silver exhibited 99.9% antimicrobial activity which was sustained up to 72 h against spoiled food derived mixed microbial culture. On the other hand, only 90% activity was observed with colloidal AgNPs due to aggregate formation. Composites displayed superior antimicrobial activity than colloid with equivalent amount of silver. Food stuff was protected from microbial spoilage for 30 days when stored in AgBC nanocomposites, whereas spoilage was noticed within 15 days for food stuff stored in regular polythene bag. Therefore, the AgBC composite having < 2% silver can be used as a lining of regular food packaging material to extend shelf life till 30 days. Toxicity due to high amount of silver can be prevented with these composites and can be safely used in healthcare applications such as food packaging, wound dressing, hospital bed lining and surgical apparels.

Biosynthesis of Silver Nanoparticles Using Pine Pollen and Evaluation of the Antifungal Efficiency.

Background: Nanoparticles have been applied to medicine, hygiene, pharmacy and dentistry, and will bring significant advances in the prevention, diagnosis, drug delivery and treatment of disease. Green synthesis of metal nanoparticles has a very important role in nanobiotechnology, allowing production of non-toxic and eco-friendly particles. Objectives: Green synthesis of silver nanoparticles (AgNPs) was studied using pine pollen as a novel, cost-effective, simple and non-hazardous bioresource. The antifungal activity of the synthesized AgNPs was investigated in vitro. Materials and Methods: Biosynthesis of AgNPs was conducted using pollen of pine (as a novel bioresource) acting as both reducing and capping agents. AgNPs were characterized using UV-visible spectroscopy, X-ray diffraction and transmission electron microscopy. In evaluation for antifungal properties, the synthesized AgNPs represented significant in vitro inhibitory effects on Neofusicoccum parvum cultures. Results: Pine pollen can mediate biosynthesis of colloidal AgNPs with an average size of 12 nm. AgNPs were formed at 22 °C and observed to be highly stable up to three months without precipitation or decreased antifungal property. AgNPs showed significant inhibitory effects against Neofusicoccum parvum. Conclusion: The first report for a low-cost, simple, well feasible and eco-friendly procedure for biosynthesis of AgNPs was presented. The synthesized AgNPs by pine pollen were nontoxic and eco-friendly, and can be employed for large-scale production. The nanoparticles showed strong effect on quantitative inhibition and disruption of antifungal growth.

Effect of Synthesized Ag Nanoparticles by Using the Different Amounts of Polyvinylpyrrolidone for Ag-Natural Rubber Hybrid Sheets and their Antibacterial Properties

Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gram-negative bacteria as Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP.

Bactericidal impact of Ag, ZnO and mixed AgZnO colloidal nanoparticles on H37Rv Mycobacterium tuberculosis phagocytized by THP-1 cell lines

The purpose of this research project was to infection of human macrophages (THP-1) cell lines by H37Rv strain of Mycobacterium tuberculosis (H37RvMTB) and find out the ratio/dilution of mixture silver (Ag NPs) and zinc oxide nanoparticles (ZnO NPs) whose ability to eliminate phagocytized bacteria compared to rifampicin. The colloidal Ag NPs and ZnO NPs were synthesized and their characteristics were evaluated. The THP-1 cell lines were infected with different concentration of H37RvMTB. Next, the infected cells were treated with different ratios/dilutions of Ag NPs, ZnO NPs and rifampicin. The THP-1 were lysed and were cultured in Lowenstein-Jensen agar medium, for eight weeks. The TEM and AFM images of NPs and H37RvMTB were supplied. It is observed that Ag NPs, 2Ag:8ZnO and 8Ag:2ZnO did not have any anti-tubercular effects on phagocytized H37RvMTB. Conversely, ZnO NPs somehow eliminated 18.7 × 104 CFU ml−1 of H37RvMTB in concentration of ∼ 0.468 ppm. To compare with 40 ppm of rifampicin, ∼ 0.663 ppm of 5Ag:5ZnO had the ability to kill of H37RvMTB, too. Based on previous research, ZnO NPs had strong anti-tubercular impact against H37RvMTB to in-vitro condition, but it was toxic in concentration of ∼ 0.468 ppm to both of THP-1 and normal lung (MRC-5) cell lines. It also seems that 5Ag:5ZnO is justified because in concentration of ∼ 0.663 ppm of 5Ag:5ZnO, phagocytized H37RvMTB into the THP-1 had died without any toxicity effects against THP-1 and also MRC-5 cell lines. It is obvious that the mixture of colloidal silver and zinc oxide NPs with ratio of 5Ag:5ZnO would be trustworthy options as anti-tubercular nano-drugs in future researches.

Green synthesis of Ag and the effect of Ag on the efficiency of TiO2 based dye sensitized solar cell

Green synthesis of silver nanoparticles (AgNPs) was carried out using the aqueous extract of Carcia papaya (commonly known as papaya) leaves as reducing and capping agent. The synthesized AgNPs colloid was mixed with titanium dioxide slurry to produce Ag:TiO2 nanocomposite. The as-synthesized AgNPs and Ag:TiO2 nanocomposite were characterized for structural, optical and morphological studies. Dye sensitized solar cells (DSSCs) were fabricated with pure TiO2 and Ag:TiO2 nanocomposite photoanodes using N719 dye and their performance was investigated. The power conversion efficiency of Ag:TiO2 nanocomposite DSSC is increased by about 33.5% when compared to the efficiency of the pure TiO2 DSSC. The electrochemical impedance spectroscopic measurements showed that Ag:TiO2 nanocomposite film effectively reduce the charge transfer resistance and also increased the lifetime of the electron.

Microbots Decorated with Silver Nanoparticles Kill Bacteria in Aqueous Media.

Water contamination is one of the most persistent problems of public health. Resistance of some pathogens to conventional disinfectants can require the combination of multiple disinfectants or increased disinfectant doses, which may produce harmful byproducts. Here, we describe an efficient method for disinfecting Escherichia coli and removing the bacteria from contaminated water using water self-propelled Janus microbots decorated with silver nanoparticles (AgNPs). The structure of a spherical Janus microbot consists of a magnesium (Mg) microparticle as a template that also functions as propulsion source by producing hydrogen bubbles when in contact with water, an inner iron (Fe) magnetic layer for their remote guidance and collection, and an outer AgNP-coated gold (Au) layer for bacterial adhesion and improving bactericidal properties. The active motion of microbots increases the chances of the contact of AgNPs on the microbot surface with bacteria, which provokes the selective Ag+ release in their cytoplasm, and the microbot self-propulsion increases the diffusion of the released Ag+ ions. In addition, the AgNP-coated Au cap of the microbots has a dual capability of capturing bacteria and then killing them. Thus, we have demonstrated that AgNP-coated Janus microbots are capable of efficiently killing more than 80% of E. coli compared with colloidal AgNPs that killed only less than 35% of E. coli in contaminated water solutions in 15 min. After capture and extermination of bacteria, magnetic properties of the cap allow collection of microbots from water along with the captured dead bacteria, leaving water with no biological contaminants. The presented biocompatible Janus microbots offer an encouraging method for rapid disinfection of water.

Antibacterial Activity of Electrochemically Synthesized Colloidal Silver Nanoparticles Against Hospital-Acquired Infections

This study evaluated the antibacterial activity of electrochemically synthesized colloidal silver nanoparticles (AgNPs) against hospital-acquired infections. Colloidal AgNPs were synthesized via a single process using bulk silver bars, bi-distilled water, trisodium citrate, and direct current voltage at room temperature. Colloidal AgNPs were characterized by transmission electron microscopy, field-emission scanning electron microscopy, and energy-dispersive x-ray analyses. The antibacterial activity of colloidal AgNPs against four bacterial strains isolated from clinical samples, including methicillin-resistant Staphylococcus aureus, Escherichia coli O157:H7, multidrug-resistant Pseudomonas aeruginosa, and carbapenem-resistant Klebsiella pneumonia, was evaluated by disc diffusion, minimum inhibitory concentration (MIC), and ultrathin sectioning electron microscopy. The results showed that the prepared AgNPs were 19.7 ± 4.3 nm in size, quasi-spherical, and of high purity. Zones of inhibition approximately 6–10 mm in diameter were found, corresponding to AgNPs concentrations of 50 μg/mL to 100 μg/mL. The MIC results revealed that the antibacterial activity of the prepared AgNPs was strongly dependent on the concentration and strain of the tested bacteria.

Silver nanoparticles induce hormesis in A549 human epithelial cells

Despite the gaps in our knowledge on the toxicity of silver nanoparticles (AgNPs), the application of these materials is fast expanding, from medicine, to food as well as the use in consumer products. It has been reported that prolonged exposure might make cells more resistant to AgNPs. This prompted us to investigate if AgNPs may give rise to a hormetic response. Two types of AgNPs were used, i.e. colloidal AgNPs and an AgNP powder. For both types of nanosilver it was found that a low dose pretreatment of A549 human epithelial cells with AgNPs induced protection against a toxic dose of AgNPs and acrolein. This protection was more pronounced after pretreatment with the colloidal AgNPs. Interestingly, the mechanism of the hormetic response appeared to differ from that of acrolein. Adaptation to acrolein is related to Nrf2 translocation, increased mRNA expression of γGCS, HO-1 and increased GSH levels and the increased GSH levels can explain the hormetic effect. The adaptive response to AgNPs was not related to an increase in mRNA expression of γGCS and GSH levels. Yet, HO-1 mRNA expression and Nrf2 immunoreactivity were enhanced, indicating that these processes might be involved. So, AgNPs induce adaptation, but in contrast to acrolein GSH plays no role.

Size and temperature dependency on structure, heat capacity and phonon density of state for colloidal silver nanoparticle in 1-Ethyl-3-methylimidazolium Hexafluorophosphate ionic liquid

Abstract Phonon detector can be designed by using colloidal silver nanoparticle (Ag NP) in presence of 1-Ethyl-3-methylimidazolium Hexafluorophosphate [EMim][PF6] ionic liquid (IL) via computational technique as the first time for many and high performance biosensors applications. Density functional theory as a quantum chemistry calculation method has been used to get the potential interaction between silver metal and ionic solvent. Molecular dynamics simulation shows that in small sizes of colloidal Ag NP in [EMim][PF6], electrical effect of IL makes one main phonon peak and in big size of colloidal Ag NP, splitting of phonon density occurs with two peaks due to the lower electrical field of IL with the surface metal. There is non-monotonic behavior for phonon mean collision time in terms of colloidal Ag NP size in IL; however, phonon mean collision time for Ag NP in gas phase decreases monotonically as the Ag NP size increases. In big size of colloidal Ag NP in IL the distance frequency of main phonon peak is closer than those in gas phase. The size of colloidal Ag NP does not have a significant effect on charge separation; cation head group and anion coincide in the vicinity of the NP for the all sizes of Ag NP. Metal dipole moment due to electrical field of IL has an effect around metal surface, reducing heat capacity of colloidal silver nanoparticle in comparison with the gas phase of Ag NP and finally heat capacity of colloidal silver nanoparticle approaches to the gas phase as the size of Ag NP increases. MD simulation shows that there is non-monotonic behavior for stabilization energy as a function of Ag NPs sizes. Our result regarding phonon DOS for Ag NP and Ag bulk are in agreement with the available experimental data.

Determination of Antifungal Activity of Silver Nanoparticles Produced from Aspergillus niger

AgNPs, over the past decades have attractive considerable interest because of their exclusive optical, electromagnetic, catalytic properties, and antifungal potency compared with other metal nanoparticles. This study was conducted to evaluate the antifungal effect of colloidal AgNPs gainst pathogenic Candida species such as Candida albicans, Candida glabrata and Candida tropicalis using disc diffusion method. Biosynthesis of AgNPs was confirmed by appearance of greyish black color of the fungal filtrate and UV visible spectrometry analysis reveals maximum absorption at 430 nm. The obtained resulted suggested that AgNPs was found to be effective against Candida species based on the diameter of the inhibition zone thus have potential implications to be used as antifungal agent.

Evaluation and Optimization of Paper-Based SERS Substrate for Potential Label-Free Raman Analysis of Seminal Plasma

Characterization and optimization of paper SERS substrate were performed in detail, in which morphologies and distribution of silver nanoparticles (AgNPs) on the paper substrate pretreated with different concentrations of NaCl and the subsequent soaking with colloidal AgNPs for different period of time were evaluated. Our results show that both NaCl concentration and soaking time with AgNPs have a significant influence on SERS enhancement, showing that an optimal EF of 2.27 × 107 was achieved when the paper substrate was treated with 20 mM NaCl and one-hour soak with AgNPs. Moreover, seminal plasma (SP) was specifically selected to evaluate the performance of paper-based SERS substrate for potential clinical detection and diagnosis. The optimization of the paper SERS substrate demonstrates potential applications in reliable on-site detection of SP and clinical diagnosis of fertility-related diseases as well.