Agglomeration Of Gold Nanoparticles Research Articles

Zn2+/GNPs nanocomposite for highly selective colorimetric detection of creatinine in urine samples of CKD patients

This research reports the fabrication of Zn2+/gold nanoparticles (GNPs) nanocomposite for colorimetric detection of creatinine (CR) in diverse media (e.g., water, artificial urine, and urine samples) between healthy subjects and chronic kidney disease (CKD) patients. The color of GNPs in suspension changed from characteristic wine-red (λabsorption = 545 ± 5 nm) to colorless or black upon the formation of nanocomposite with Zn2+ ions. However, upon addition of CR to Zn2+/GNPs nanocomposite suspension, the characteristic wine-red color of GNPs was restored. Our experimental analysis evidently validated the hypothesis on Zn2+ induced agglomeration of GNPs and their subsequent anti-agglomeration upon the addition of CR to the Zn2+/GNPs. Overall, our approach offered highly sensitive recognition of CR with a limit of detection of 2 µg·mL−1 (R2 = 0.95) along with excellent stability (>three months), selectivity (in the presence of interfering biochemicals (e.g., urea,ascorbic acid, and glucose, glutathione, Na+, K+, Ca2+, Mg2+, PO43−, and SO4 2−)), and reproducibility (relative standard deviation ∼ 9 %). Finally, the great potential of our method for CR recognition was also confirmed by good agreement (R2 = 0.95) with the gold standard ‘Jaffe’ method along with the Bland-Altman analysis for urine samples between health subjects (n = 15) and CKD patients (n = 11). In near future, a quantitative lateral flow biosensor is expected to be developed for non-invasive detection of CR through the integration of the proposed approach with the machine learning tools.

New insights into thermal processes of metal deposits on h-BN/Rh(1 1 1): A comparison of Au and Rh

In this paper the thermal properties of Au and Rh deposits are compared on hexagonal boron nitride (h-BN) “nanomesh” prepared on Rh(111), applying STM, XPS, low energy ion scattering (LEIS), LEED, and DFT. At room temperature, both metals essentially follow Volmer-Weber (3D) growth. Upon subsequent annealing, agglomeration (sintering), intercalation, and desorption are competing surface processes for both metals. For the more reactive Rh, we suggest an additional encapsulation mechanism: between 600 K and 750 K, fragments of decomposed h-BN diffuse locally from the bottom onto the metal clusters covering them partially. STM data indicates that agglomeration of gold nanoparticles proceeds faster compared to rhodium. At higher temperatures (∼1050 K–1100 K), all non-desorbing gold atoms diffuse below h-BN, even for large initial coverages. On the other hand, for larger Rh deposits (≥5 ML), the outermost layer always contains Rh. Accumulation of gold at the interface between h-BN and Rh(111) significantly enhances the thermal stability of h-BN, attributed to the lower reactivity of Au in the decomposition of h-BN compared to Rh(111). At elevated substrate temperatures, intercalation of individual adatoms takes place during deposition, which requires higher temperatures for rhodium due to its slower diffusion and higher probability of nucleation.

Nanoparticle-Based Plasmonic Biosensor for the Unamplified Genomic Detection of Carbapenem-Resistant Bacteria.

Antimicrobial resistance (AMR) is a global public health issue, and the rise of carbapenem-resistant bacteria needs attention. While progress is being made in the rapid detection of resistant bacteria, affordability and simplicity of detection still need to be addressed. This paper presents a nanoparticle-based plasmonic biosensor for detecting the carbapenemase-producing bacteria, particularly the beta-lactam Klebsiella pneumoniae carbapenemase (blaKPC) gene. The biosensor used dextrin-coated gold nanoparticles (GNPs) and an oligonucleotide probe specific to blaKPC to detect the target DNA in the sample within 30 min. The GNP-based plasmonic biosensor was tested in 47 bacterial isolates: 14 KPC-producing target bacteria and 33 non-target bacteria. The stability of GNPs, confirmed by the maintenance of their red appearance, indicated the presence of target DNA due to probe-binding and GNP protection. The absence of target DNA was indicated by the agglomeration of GNPs, corresponding to a color change from red to blue or purple. The plasmonic detection was quantified with absorbance spectra measurements. The biosensor successfully detected and differentiated the target from non-target samples with a detection limit of 2.5 ng/μL, equivalent to ~103 CFU/mL. The diagnostic sensitivity and specificity were found to be 79% and 97%, respectively. The GNP plasmonic biosensor is simple, rapid, and cost-effective in detecting blaKPC-positive bacteria.

Functional confinement of a zinc-oxide-supported gold catalyst enhances the direct synthesis of hydrogen peroxide

Due to the intensive energy consumption and environmental unfriendliness of the current industrial anthraquinone process for producing hydrogen peroxide, it is of interest to develop a clean and efficient alternative. Herein, we report that a zinc-oxide-supported gold catalyst encapsulated by a silica overlayer efficiently catalyzes the direct synthesis of hydrogen peroxide from carbon monoxide, oxygen, and water. Detailed characterizations demonstrate that the confinement effect of the silica overlayer may enhance hydrogen peroxide productivity by limiting the agglomeration of gold nanoparticles, inhibiting the hydrogen peroxide degradation activity, and improving the hydrophilicity of the catalyst surface. Isotope-labeling experiments and theoretical calculations reveal that both oxygen atoms in hydrogen peroxide come from molecular oxygen, and that a consecutive hydrogenation process is followed. This work poses a facile strategy to construct highly active catalysts for the direct synthesis of hydrogen peroxide, employing the confinement effects of an overlayer.

High-efficiency SERS platform based on 3D porous PPDA@Au NPs as a substrate for the detection of pesticides on vegetables.

Nowadays, the presence of highly toxic and persistent residues of pesticides in water and food around the world is becoming a serious problem, and so their rapid and sensitive detection is critical to human health. In this work, a 3D composite nanoparticle of porous PDA (polydopamine) microspheres and Au NPs (PPDA@Au NPs) was proposed as a SERS substrate to detect pesticides. Porous PDA as a substrate was first synthesized with F127 (Pluronic F127), dopamine hydrochloride, and 1,3,5-TMB (1,3,5-trimethylbenzene) under weakly alkaline conditions by a one-step method. Then, HAuCl4 was in situ reduced in the pores of PPDA spheres and grew sequentially for effecting the reducibility of PPDA. As a result, uniform 3D PPDA@Au NPs with "hot spots" were successfully synthesized as SERS substrates, which could effectively avoid the agglomeration of gold nanoparticles to greatly improve the sensitivity and uniformity of the SERS platform. At the same time, methyl parathion, 4-chlorophenol, and 2,4-D as representatives of pesticides were detected with the proposed PPDA@Au NP-based SERS platform, with detection limits lower than 7.26, 7.52, and 11 ng mL-1, separately. The current work presents a simple preparation method to prepare sensitive and uniform SERS platform PPDA@Au NPs, which have potential for applications in actual pesticide and drug testing.

Highly-sensitive electrochemiluminescence biosensor for detection of inosine monophosphate in meat based on graphdiyne/AuNPs/luminol nanocomposites

Inosine monophosphate (IMP), as a critical umami substance, is one of the most important indicators for evaluating the quality of meat products. Here, a sensitive electrochemiluminescence (ECL) biosensor based on graphdiyne (GDY)/AuNPs/luminol nanocomposites was constructed to detect IMP. The GDY/AuNPs/luminol nanocomposites were synthesized by using simple one-pot method. GDY utilized its 2D framework to disperse and fix gold nanoparticles, which inhibited the agglomeration of gold nanoparticles and greatly improved its stability and catalytic properties. Importantly, GDY/AuNPs/luminol nanocomposites showed excellent catalytic ability and superior ECL activity towards luminol-H2O2 systems due to the synergistic effect of GDY and AuNPs. Under optimal conditions, the prepared biosensor exhibited a wide linear range from 0.01 g/L to 20 g/L, a satisfactory limit detection of 0.0013 g/L, as well as an excellent specificity. Moreover, we carried out the precise analysis of IMP in actual meat samples with acceptable results compared to the liquid chromatography. We believe that this work could offer an efficient ECL platform for accurate and reliable report of IMP levels, which is significant for maintaining food quality and safety.

WITHDRAWN: Design and evaluation of a novel Kaolin-chitosan/gold nanocomposite for the treatment of human lung cancer

• Kaolin-CS/Au nanocomposite have antioxidant potentials against free radicals DPPH. • Kaolin-CS/Au nanocomposite have anti-human lung cancer properties. Kaolin-chitosan (Kaolin-CS) is an interesting bio composite with applications in formulating the anticancer supplements. Thus, the purpose of this study is to prepare Kaolin-CS/Au nanocomposite by adding gold nanoparticles (Au NPs) to modify Kaolin with chitosan. The significance of this study is the novel initiative to combine the gold nanoparticle with inexpensive kaolin clay and utilization of them as anticancer agent. Through transmission electron microscopy, we found that the presence of CS could effectively prevent the agglomeration of gold nanoparticles on the surface of Kaolin. The Kaolin-CS/Au nanocomposite were characterized by electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), elemental mapping, X-ray diffraction (XRD) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). In the cellular and molecular part of the recent study, the treated cells with Kaolin-CS/Au nanocomposite were assessed by MTT assay for 48h about the cytotoxicity and anti-human lung carcinoma properties on normal (HUVEC) and lung carcinoma cell lines i.e. NCI-H661, NCI-H1563, and NCI-H1299. The IC50 of Kaolin-CS/Au nanocomposite were 138, 144, and 138 µg/mL against NCI-H661, NCI-H1563, and NCI-H1299 cell lines, respectively. The viability of malignant lung cell lines reduced dose-dependently in the presence of Au NPs-Kaolin nanocomposite.

Modification of Aerosol Gold Nanoparticles by Nanosecond Pulsed-Periodic Laser Radiation.

This study investigates the processes of interaction of nanosecond pulsed-periodic laser radiation with the flow of aerosol agglomerates of gold nanoparticles synthesized in a spark discharge. Nanoparticles in a gas flow are spatially separated nano-objects whose interaction with each other and with the walls of an experimental cell was insignificant. Therefore, the energy absorbed by nanoparticles was used only for their own heating with further shape and size modification and on heat transfer to the surrounding gas. In the research, we used laser radiation with wavelengths of 527 and 1053 nm at pulse energies up to 900 µJ and pulse repetition rates up to 500 Hz. The dynamics of changes in the nanoparticles size during their sintering process depending on the laser pulses energy is characterized by an S-shaped shrinkage curve. Complete sintering of the initial agglomerates with their transformation into spherical nanoparticles is achieved by a series of impacting laser pulses. The result of nanoparticles’ laser modification is largely determined by the pulse energy and the efficiency of the nanoparticles’ radiation absorption.

Glycerol Oxidation over Supported Gold Catalysts: The Combined Effect of Au Particle Size and Basicity of Support

Gold nanoparticles supported on various oxides (CeO2, CeO2/TiO2, MgO, MgO/TiO2, La2O3, La2O3/TiO2) (with 4 wt.% Au loading) were investigated in the liquid (aqueous) phase oxidation of glycerol by molecular oxygen under mild conditions, in the presence of alkaline earth (CaO, SrO and MgO) or alkaline (NaOH) bases. Full conversion and selectivity between 38 and 68% to sodium glycerate were observed on different Au supported catalysts (Au/MgO/TiO2, Au/La2O3/TiO2, Au/CeO2 and Au/CeO2/TiO2). The combined effect of Au particle size and basicity of the support was suggested as the determining factor of the activity. Agglomeration of gold nanoparticles, found after the reaction, led to the deactivation of the catalysts, which prevents the further oxidation of sodium glycerate into sodium tartronate. Promising results were obtained with the use of alkaline earth bases (CaO, SrO, MgO), leading to the formation of free carboxylic acids instead of salts, which are formed in the presence of the more usual base, NaOH.

G-quadruplex-based assay combined with aptamer and gold nanoparticles for Escherichia coli K88 determination.

A colorimetric method was developed usingG-quadruplex and gold nanoparticles (AuNPs) for determination of Escherichia coli K88 (ETEC K88). It was composed of two modules: (1) an aptamer as biorecognizing element and (2) a capturing DNA (modified with AuNPs at 5') as a transducer. In the absence of target bacteria, the aptamer can form stable double strands with capturing DNA, preventing the binding of capturing DNA to the G-quadruplex. However, the double strands of capturing DNA and aptamer are untied due to the stronger binding of aptamers to bacteria in the presence of target bacteria. As a result, the G-quadruplex binds to capture DNA and leads to the aggregation and color change of AuNPs, which can be monitored by a spectrophotometer or visualization. The quantitative determination was achieved by monitoring the optical density change of AuNPs solution at 524nm after target addition. Under optimal conditions, the method has a low detection limit (1.35 × 102CFUmL-1) and a linear response in the range102 to 106CFUmL-1. Graphical abstract The manuscripts describe a colorimetric method for the detection of ETEC K88 by using intermolecular G-quadruplex to induce the agglomeration of gold nanoparticles, which can be directly used to determine the presence of bacteria with our naked eyes.

Highly stable MoS2@PDA composite for enhanced reduction of AuCl4−

MoS2 has attracted tremendous attention in reducing AuCl4−, however, it suffers from poor stability in solutions. In this work, MoS2 nanosheet wrapped with polydopamine (MoS2@PDA composite) was successfully prepared by simple hydro-thermal synthesis. Compared to pure MoS2, the as-synthesized MoS2@PDA composite exhibited not only excellent stability, but also superb AuCl4− reduction capacity. With the warp of PDA, the thermal stability of the composite was improved obviously, and dissolution of the composite in aqueous solution hardly occurs. Moreover, the reduction of AuCl4− by MoS2@PDA composite could reach equilibrium in 90 min, and the maximum reduction was about 3800 mg/g, and the reaction was intensely pH-dependent. In addition, gold nanoparticles were widely distributed on the surface of MoS2@PDA composite, which could effectively prevent the agglomeration of gold nanoparticles. This finding might point out the possibility of applying MoS2@PDA composite as stable anti-agglomeration substrate for gold nanoparticles.

Divalent ion-induced aggregation of gold nanoparticles for voltammetry Immunosensing: comparison of transducer signals in an assay for the squamous cell carcinoma antigen.

A method is described for the electrochemical determination of squamous cell carcinoma (SCC) antigen, and by testing the effect of 30nm gold nanoparticles (GNPs). Three comparative studies were performed in the presence and absence of GNPs, and with agglomerated GNPs. The divalent ion Ca(II) was used to induce a strong agglomeration of GNPs, as confirmed by colorimetry and voltammetry. Herein, colorimetry was used to test the best amount of salt needed to aggregate the GNPs. Despite, voltammetry was used to determine the status of biomolecules on the sensor. The topography of the surface of ZnO-coated interdigitated electrodes was analyzed by using 3D-nano profilometry, scanning electron microscopy, atomic force microscopy and high-power microscopy. The interaction between SCC antigen and antibody trigger vibrations on the sensor and cause dipole moment, which was measured using a picoammeter with a linear sweep from 0 to 2V at 0.01V step voltage. The sensitivity level was 10 fM by 3σ calculation for the dispersed GNP-conjugated antigen. This indicates a 100-fold enhancement compared to the condition without GNP conjugation. However, the sensitivity level for agglomerated GNPs conjugated antibody was not significant with 100 fM sensitivity. Specificity was tested for other proteins in serum, namely blood clotting factor IX, C-reactive protein, and serum albumin. The SCC antigen was quantified in spiked serum and gave recoveries that ranged between 80 and 90%. Graphical abstractSchematic representation of SCC (squamous cell carcinoma) antigen determination using divalent ion induced agglomerated GNPs. Sensitivity increment depends on the occurrence of more SCC antigen and antibody binding event via GNPs integration. Notably, lower detection limit was achieved at femto molar with proper orientation of biological molecules.

The catalytic performance of isolated-dispersed Au on nanosized CeO2 for CO preferential oxidation in H2-rich stream

Nanosized CeO2 and supported Au catalysts were synthesized and their catalytic performance for CO preferential oxidation in H2-rich streams was evaluated. Transmission electron microscope (TEM), N2 isothermal adsorption/desorption, X-ray diffraction (XRD), temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and in-situ DRIFTS techniques were adopted to characterize their structure property, redox property as well as dispersion and valence states of the active Au species. The results demonstrate the strong interaction between highly dispersed gold species (grain size <2 nm) and CeO2 in catalysts with low gold loading, which promotes the reduction of surface and sub-surface oxygen and the stabilization of high-valent Au3+ species. Meanwhile, it creates more lattice defects and benefits to the enhanced mobility of lattice oxygen and the activation of gas oxygen, thus contributing to the low-temperature CO preferential oxidation. However, over high Au content (≥0.6%) would lead to the agglomeration of gold nanoparticles and the formation of Au0 species, which weakens the gold-ceria interaction and decreases the active sites. On the other hand, the formation of Au0 species with large grain size would accelerate the dissociation of H2, which is the main reason for the decreasing of O2 selectivity toward CO over Au/CeO2 catalysts.

SERS-Active-Charged Microgels for Size- and Charge-Selective Molecular Analysis of Complex Biological Samples.

Surface-enhanced Raman scattering (SERS) provides a dramatic increase of Raman intensity for molecules adsorbed on nanogap-rich metal nanostructures, serving as a promising tool for molecular analysis. However, surface contamination caused by protein adsorption and low surface concentration of small target molecules reduce the sensitivity, which severely restricts the use of SERS in many applications. Here, charged microgels containing agglomerates of gold nanoparticles (Au NPs) are designed using droplet-based microfluidics to provide a reliable SERS substrate with molecular selectivity and high sensitivity. The limiting mesh size of hydrogel enables the autonomous exclusion of large proteins and the charged matrix concentrates oppositely charged small molecules through electrostatic attraction. As nanogaps among Au NPs in the agglomerates enhance Raman intensity, Raman spectrum of the adsorbed molecules is selectively measured with high sensitivity in the absence of interruption from adhesive proteins. Therefore, the SERS-active-charged microgels can be used for direct analysis of pristine biological samples without the pretreatment steps of separation and concentration, which are commonly a prerequisite for Raman analysis. For the purpose of demonstration, a direct detection of fipronil sulfone with partial negative charges, a metabolite of toxic insecticide, dissolved in eggs using the positively charged microgels without any pretreatment of the samples, is shown.

Enhancement of the Sensitivity of a Lateral Flow Immunoassay by Using the Biotin–Streptavidin System

A new approach based on the use of a complex conjugate is proposed for improving the sensitivity of a lateral flow immunoassay. The complex conjugate is an agglomerate of gold nanoparticles formed by binding biotinylated antibodies labeled with gold nanoparticles to streptavidin. The amplification of the analytical signal is due to the accumulation of the agglomerates of gold nanoparticles in the test zone of the strip. The proposed test system is implemented in the lateral flow immunoassay of a model protein, procalcitonin. This system makes it possible to perform the analysis in a single step without resorting to additional reagents or manipulations. The procalcitonin detection range was 0.5–100 ng/mL and the limit of detection was 0.25 ng/mL; i.e., the sensitivity of the method is four times better than that of the conventional lateral flow immunoassay, in which spherical gold nanoparticles are used as a label.

Insight on agglomerates of gold nanoparticles in glass based on surface plasmon resonance spectrum: study by multi-spheres T-matrix method

The formation of a localized surface plasmon resonance (SPR) spectrum of randomly distributed gold nanoparticles in the surface layer of silicate float glass, generated and implanted by UV ArF-excimer laser irradiation of a thin gold layer sputter-coated on the glass surface, was studied by the T-matrix method, which enables particle agglomeration to be taken into account. The experimental technique used is promising for the production of submicron patterns of plasmonic nanoparticles (given by laser masks or gratings) without damage to the glass surface. Analysis of the applicability of the multi-spheres T-matrix (MSTM) method to the studied material was performed through calculations of SPR characteristics for differently arranged and structured gold nanoparticles (gold nanoparticles in solution, particles pairs, and core–shell silver–gold nanoparticles) for which either experimental data or results of the modeling by other methods are available. For the studied gold nanoparticles in glass, it was revealed that the theoretical description of their SPR spectrum requires consideration of the plasmon coupling between particles, which can be done effectively by MSTM calculations. The obtained statistical distributions over particle sizes and over interparticle distances demonstrated the saturation behavior with respect to the number of particles under consideration, which enabled us to determine the effective aggregate of particles, sufficient to form the SPR spectrum. The suggested technique for the fitting of an experimental SPR spectrum of gold nanoparticles in glass by varying the geometrical parameters of the particles aggregate in the recurring calculations of spectrum by MSTM method enabled us to determine statistical characteristics of the aggregate: the average distance between particles, average size, and size distribution of the particles. The fitting strategy of the SPR spectrum presented here can be applied to nanoparticles of any nature and in various substances, and, in principle, can be extended for particles with non-spherical shapes, like ellipsoids, rod-like and other T-matrix-solvable shapes.

Suppression of gold nanoparticle agglomeration and its separation via nylon membranes

Abstract Use of ultraporous nylon membrane is one of the most widely employed techniques for removal of hard and soft nanoparticles in the semiconductor industry, and the accurate determination of membrane pore size is necessary in order to avoid manufacturing defects caused by contamination. The gold nanoparticle has several benefits for the evaluation of polymeric membranes; however, the nanoparticles agglomerate easily on the nylon membrane and make it difficult to evaluate the membrane precisely. The properties of 2-amino-2-hydroxymethyl-1,3-propanediol (ADP) ligand in gold nanoparticle solution were systematically investigated, and ADP was utilized for improved evaluation of the nylon membranes. Nylon membrane used in this study was prepared by phase inversion techniques. Ultrathin dense layer on top of the membrane surface and Darcy structures in the microporous membrane support were observed. The gold particle rejection was carried out at various pH values from 4 to 14 and higher rejection was observed at pH 4 and 8. The suppression of gold colloid agglomeration using ADP and monodispersity of gold colloids was also analyzed by confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). van der Waals interaction energy of the particles was reduced in the addition of ADP. The presence of ADP ligand in the gold solutions prevented the agglomeration of gold nanoparticles and reduced the adsorption of the particles on the nylon membrane surface, leading to precise evaluation of membrane pore sizes.

Rapid Detection of Staphylococcus aureus Genomic DNA Using Peptide Nucleic Acid and Gold Nanoparticles

Staphylococcus aureus is a Gram-positive bacterium and is known to affect almost all mammalian species. This organism causes a multitude of cutaneous and systemic human diseases and is the main etiological agent in causing bovine mastitis causing heavy economic loss to dairy industry. Microbiological detection of S. aureus is time consuming and molecular diagnostic technique requires skilled personnel and costly equipment. Peptide nucleic acids (PNA) are DNA analogues with charged neutral polyamide backbone. Free PNA induces aggregation of citrate capped colloidal gold nanoparticles. Using this property of PNA, rapid, simple, and an easy method of detecting S. aureus genomics was developed in the present study. PNA concentration of 1 μM induced clear colour change of gold nanoparticles from brick red to blue colour. Visual detection limit of complementary target DNA inhibiting PNA induced agglomeration of gold nanoparticles was 0.25 μM whereas, spectral detection limit was even at lower concentration of 0.1 μM. PNA induced aggregation was gradually reduced with increasing concentration of non-complementary DNA and concentration of non-complementary DNA of 2.5 times more than PNA concentration was able to prevent the PNA induced aggregation of gold nanoparticles. Sensitivity detection limit of this colorimetric assay in detecting genomic DNA of S. aureus was 106 cells visually and 104 cells spectrophotometrically. The test was performed with 20 field isolates of staphylococcal species. Out of 20 isolates, 16 were identified as S. aureus specifically. This assay was robust and had the advantage of being simple, fast and sensitive.

Colorimetric detection of active botulinum neurotoxin using Cu2+ mediated gold nanoparticles agglomeration

We report a colorimetric detection of functional botulinum neurotoxin (BoNT) based on its proteolytic activity. Active BoNT can enzymatically cleave SNAptide, a short peptide with 15 amino acids. The cleaved peptides subsequently induced the agglomeration of gold nanoparticles, allowing a colorimetric signal that can be discerned by the naked eye at the low concentration of 1ng/mL (6.67pM), and achieve low limit of detection at 0.25ng/mL (1.67pM 3 σ/s) by spectral absorbance. This colorimetric detection will provide a simple and promising method for applications at low-resource sites.

Plasmonic nanoparticle incorporation into inverted hybrid organic–inorganic solar cells

To enhance solar harvesting in hybrid organic–inorganic photovoltaic devices we positioned plasmonic gold nanostructures in titania-conjugated polymer devices. Two plasmonic structures were judiciously designed and studied. In the first, agglomerates of gold nanoparticles, ∼150nm in diameter, were positioned as scattering clusters at the active layer/ITO electrode interface. In the second approach, 5nm isolated Au particles were suspended inside the hybrid active layer to induce localized plasmonic field enhancement. The location of the particles, size and distribution in the film was confirmed using scanning and transmission electron microscopy and X-ray scattering. The optical absorption measurements confirmed that both plasmonic structures enhance light harvesting, and photovoltaic devices utilizing each of the approaches showed improved photocurrent generation. Finite difference time domain simulations have corroborated that scattering-based and near-field absorption enhancements occur in the active layer, in good agreement with the measured absorption. Finally, combining both approaches to fabricate a hybrid photovoltaic device with both plasmonic nanostructures, i.e. Au NPs both in and on the active layer, resulted in a twofold increase in photocurrent generation.