White Light Irradiation Research Articles

Broad Dual Emission by Codoping Cr3+ (d→d) and Bi3+ (s→p) in Cs2 Ag0.6 Na0.4 InCl6 Double Perovskite.

A phosphor emitting both white light and broad near-infrared (NIR) radiation can simultaneously provide visual inspection and early signs of rotting of food products. The broad NIR emission is absorbed by the vibrational overtones of water molecules present in food items, providing the non-invasive image contrast to assess the food freshness. Here we design a phosphor, namely, Cr3+ -Bi3+ -codoped Cs2 Ag0.6 Na0.4 InCl6 , that simultaneously emit warm white light and broad NIR (1000 nm) radiation with quantum yield 27 %. This dual emitter is designed by combining the features of s2 -electron (Bi3+ ) and d3 -electron (Cr3+ ) doping in a weak crystal field of the halide perovskite host. excitation of Bi3+ , using a commercial 370 nm ultraviolet light-emitting-diodes (UV-LED), yields both the emissions. A fraction of the excited Bi3+ dopants emit the warm white light, and the other fraction transfers its energy non-radiatively to Cr3+ . Then the Cr3+ de-excites emitting broad NIR emission. Temperature dependent (6.4-300 K) photoluminescence in combination with Tanabe-Sugano diagram show that the Cr3+ experiences a weak crystal field ( =2.2), yielding the NIR emission. As a proof of concept, we fabricated a panel containing 122 phosphor-converted LEDs, demonstrating its capability to inspect food products.

Broad Dual Emission by Codoping Cr3+ (d→d) and Bi3+ (s→p) in Cs2Ag0.6Na0.4InCl6 Double Perovskite

AbstractA phosphor emitting both white light and broad near‐infrared (NIR) radiation can simultaneously provide visual inspection and early signs of rotting of food products. The broad NIR emission is absorbed by the vibrational overtones of water molecules present in food items, providing the non‐invasive image contrast to assess the food freshness. Here we design a phosphor, namely, Cr3+‐Bi3+‐codoped Cs2Ag0.6Na0.4InCl6, that simultaneously emit warm white light and broad NIR (1000 nm) radiation with quantum yield 27 %. This dual emitter is designed by combining the features of s2‐electron (Bi3+) and d3‐electron (Cr3+) doping in a weak crystal field of the halide perovskite host. excitation of Bi3+, using a commercial 370 nm ultraviolet light‐emitting‐diodes (UV‐LED), yields both the emissions. A fraction of the excited Bi3+ dopants emit the warm white light, and the other fraction transfers its energy non‐radiatively to Cr3+. Then the Cr3+ de‐excites emitting broad NIR emission. Temperature dependent (6.4–300 K) photoluminescence in combination with Tanabe‐Sugano diagram show that the Cr3+ experiences a weak crystal field ( =2.2), yielding the NIR emission. As a proof of concept, we fabricated a panel containing 122 phosphor‐converted LEDs, demonstrating its capability to inspect food products.

Molecular Engineering of AIE Photosensitizers for Inactivation of Rabies Virus.

Rabies is a zoonotic neurological disease caused by the rabies virus (RABV) that is fatal to humans and animals. While several post-infectiontreatment have been suggested, developing more efficient and innovative antiviral methods are necessary due to the limitations of current therapeutic approaches. To address this challenge, a strategy combining photodynamic therapy and immunotherapy, using a photosensitizer (TPA-Py-PhMe) with high type I and type II reactive oxygen species (ROS) generation ability isproposed. This approach can inactivate the RABV by killing the virus directly and activating the immune response. At the cellular level, TPA-Py-PhMe can reduce the virus titer under preinfection prophylaxis and postinfection treatment, with its antiviral effect mainly dependent on ROS and pro-inflammatory factors. Intriguingly, when mice areinjected with TPA-Py-PhMe and exposed to white light irradiation at three days post-infection, the onset of disease isdelayed, and survival rates improved to some extent. Overall, thisstudy shows that photodynamic therapy and immunotherapy open new avenues for future antiviral research.

From cell membrane to mitochondria: Time-dependent AIE photosensitizer for fluorescence imaging and photodynamic anticancer therapy

Aggregation-induced emission photosensitizers (AIE-PSs) targeting different subcellular organelles with time-dependent manner are highly promising for clinical applications but rarely reported. Herein, we designed and synthesized the near-infrared (NIR) emission AIE-PS (CTQ-S) with broad absorption and excellent type I reactive oxygen species (ROS) generation efficiency that was superior to the widely used PS (Rose Bengal and Chlorine 6). With short-term incubation, CTQ-S anchored on the cell membrane (Rr: 0.843, Rr is for Pearson correlation coefficient) and gradually entered the mitochondria (Rr: 0.937) of cancer cells, showing excellent time-dependent fluorescence fluorescent imaging effect. Furthermore, CTQ-S realized the selective photodynamic therapy (PDT) effect in a time-dependent manner under white light irradiation. This work provided a new way for cancer cells fluorescence imaging and PDT.

Nature sunlight-driven polymer/TiO2 antimicrobial agent for the killing of multidrug-resistant bacteria with enhanced photocatalytic activity

Photocatalytic antimicrobial technology is one of the most effective methods to treat multidrug resistance (MDR) bacteria-caused infections. Nevertheless, its practical application is hindered because of the low light utilization rate and the weak photocatalytic antimicrobial properties. In this work, a heterojunction photocatalyst consisting of an organic-conjugated polymer and a biological semiconductor is prepared to kill MDR bacteria under sunlight. The organic semiconductor poly[2,11′-thiopheneethylenethiophene-alt-2,5-(3-carboxyl)thiophene] (PThC) with carboxyl can via weak interactions such as hydrogen bonding combine with the surface hydroxyl group of TiO2 to achieve a high stability. The PThC/TiO2 photocatalyst possesses improved antibacterial activity because of the formation of heterostructure that achieves visible region spectrum absorption, and the reduction of the photocarrier recombination rate to produce more reactive oxygen species. The use of PThC/TiO2 in the inactivation of Methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) revealed that the antibacterial activity was greatest when the PThC/TiO2 dose was 30% and the concentration was 0.2 mg/mL. Under LED white light irradiation, 7.31 log MRSA (100%) could be inactivated within 30 min, and the inactivation efficiency of E. coli reached 100% within 3 h. Under natural sunlight, it also has a significant antimicrobial action.

Type-I organic photosensitizers with two complementary reactive oxygen species based on donor-acceptor (D-A) molecules

Type-I photosensitizers (PSs) are considered to be a better choice for photodynamic therapy (PDT) because they can efficiently generate reactive oxygen species (ROS) in the hypoxia condition of tumor, showing less oxygen dependence. However, there are relatively few reported highly efficient type-I organic PSs, especially those simultaneously generated two or more species of type-I ROS. Herein, based on electron-acceptor of 9,10-phenanthrenequinone (PQ), a D-A-D structural type-I PS of PPQ constructed from electron-donor of 9-phenyl-carbazole (PCZ) was firstly developed and could simultaneously produce two type-I ROS under white light irradiation. As the generated ROS of hydroxyl radical (•OH) and superoxide anion radical (O2•−) possessed complementary oxidizing ability and radical lifetime, PPQ showed excellent PDT effects for tumor cells under normoxia or hypoxia. The ability of ROS generation and PDT performance of PPQ were better than those of another PQ derivative (TPQ) constructed with common electron-donor triphenylamine (TPA). More importantly, experiments in aqueous solution and vitro both revealed that •OH generated not only from the well-known transformation of O2•− but also direct electron transition from water to triplet excited PS, which demonstrated the oxygen dependence of type-I PSs more clearly. This new type-I PS offers an opportunity to obtain deep insights of the mechanism of type-I PSs, and provides a new strategy for development of type-I PSs.

AIE-Active Glycomimetics Triggered Bacterial Agglutination and Membrane-Intercalating toward Efficient Photodynamic Antiseptic.

Opportunistic infections caused by Pseudomonas aeruginosa (P. aeruginosa) are particularly difficult to treat due to the altered membrane permeability and inherent resistance to conventional antibiotics. Here, a cationic glycomimetics is designed and synthesized with aggregation-induced emission (AIE) characteristics namely TPyGal, which self-assembles into the spherical aggregates with galactosylated surface. TPyGal aggregates can effectively cluster P. aeruginosa through multivalent carbohydrate-lectin interactions and auxiliary electrostatic interactions and subsequently trigger membrane-intercalating, which results in efficient photodynamic eradication of P. aeruginosa under white light irradiation by in situ singlet oxygen (1 O2 ) burst to disrupt bacterial membrane. Furthermore, the results demonstrate that TPyGal aggregates promote the healing of infected wounds, indicating the potential for clinical treatment of P. aeruginosa infections.

Photoactive hourglass-type M{P 4Mo 6} 2 networks for efficient removal of hexavalent chromium

The exploration of high-efficiency photocatalysts to drive the conversion of highly toxic heavy metal hexavalent chromium (Cr(VI)) in wastewater to low-toxic trivalent chromium (Cr(III)) is of great significance for purifying water that contains emerging contaminants. Herein, four hourglass-type phosphomolybdate-based hybrid networks—(H₂bpe)₂[M(H₂O)₃]₂{M[P₄Mo₆O₃₁H₇]₂}·8H₂O <strong>(</strong>M = Mn for <strong>1</strong>, Co for <strong>2</strong>) and (Hbpe)(H₂bpe)Na[M(H₂O)₃]₂{M[P₄Mo₆O₃₁H₇]₂}·9H₂O <strong>(</strong>M = Mn for <strong>3</strong>, Co for <strong>4</strong>; {M[P₄Mo₆O₃₁H₇]₂}⁸⁻ (abbr. M{P₄Mo₆}₂); bpe = 1,2-di(4-pyridyl)ethylene)—were hydrothermally synthesized as heterogeneous photocatalysts for Cr(VI) reduction. A structural analysis showed that the four hybrids <strong>1</strong>–<strong>4</strong> exhibited two-dimensional inorganic sheet-like structures with a 3,6-connected <i>kgd</i> topology built of hourglass phosphomolybdate clusters having different central metal ions, which further interacted with organic bpe cations via abundant hydrogen-bonding interactions to extend the structure to a three-dimensional (3D) supramolecular network. The four hybrids displayed excellent redox properties and wide visible-light absorption. When used as heterogeneous photocatalysts, hybrids <strong>1</strong>–<strong>4</strong> exhibited excellent photocatalytic activity for Cr(VI) reduction under 10 W white light irradiation, with reduction rates of 91% for <strong>1</strong>, 74% for <strong>2</strong>, 90% for <strong>3,</strong> and 71% for <strong>4</strong>, respectively, within 80 min. The Cr(VI) reduction reaction over hybrids <strong>1</strong>–<strong>4</strong> followed the pseudo first-order kinetics model with reaction rate constants <i>k</i> of 0.0237 min⁻¹ for <strong>1</strong>, 0.0143 min⁻¹ for <strong>2</strong>, 0.0221 min⁻¹ for <strong>3</strong> and 0.0134 min⁻¹ for <strong>4</strong>, respectively. The Mn{P₄Mo₆}₂-based hybrids <strong>1</strong> and <strong>3</strong> showed better photocatalytic performance than the Co{P₄Mo₆}₂-based hybrids <strong>2</strong> and <strong>4</strong>, along with excellent recycle stability. This mechanism study shows that the different central metals M in the M{P₄Mo₆}₂ cluster have a considerable impact on photocatalytic performance due to their regulation effect on the electronic structure. This work provides evidence for the important role of the central metal in hourglass-type phosphomolybdate in the regulation of photocatalytic performance, and it brings inspiration for the design of highly efficient photocatalysts based on polyoxometalates.

Antileishmanial activity of tetra-cationic porphyrins with peripheral Pt(II) and Pd(II) complexes mediated by photodynamic therapy

Leishmaniasis is a neglected disease that impacts more than one billion people in endemic areas of the globe. Several drawbacks are associated with the currently existing drugs for treatment such as low effectiveness, toxicity, and the emergence of resistant strains that demonstrate the importance of looking for novel therapeutic alternatives. Photodynamic therapy (PDT) is a promising novel alternative for cutaneous leishmaniasis treatment because its topical application avoids potential side effects generally associated with oral/parenteral application. A light-sensitive compound known as photosensitizer (PS) interacts with light and molecular oxygen to generate reactive oxygen species (ROS), which promote cell death by oxidative stress through PDT approaches. Here, for the first time, we demonstrate the antileishmanial effect of tetra-cationic porphyrins with peripheral Pt(II)- and Pd(II)-polypyridyl complexes using PDT. The isomeric tetra-cationic porphyrins in the meta positions, 3-PtTPyP, and 3-PdTPyP, exhibited the highest antiparasitic activity against promastigote (IC50-pro = 41.8 nM and 46.1 nM, respectively) and intracellular amastigote forms (IC50-ama = 27.6 nM and 38.8 nM, respectively) of L. amazonensis under white light irradiation (72 J cm–2) with high selectivity (SI > 50) for both forms of parasites regarding mammalian cells. In addition, these PS induced the cell death of parasites principally by a necrotic process in the presence of white light by mitochondrial and acidic compartments accumulation. This study showed that porphyrins 3-PtTPyP and 3-PdTPyP displayed a promising antileishmanial-PDT activity with potential application for cutaneous leishmaniasis treatment.

A viscosity-sensitive and mitochondria-targeted AIEgen effectuated fatty liver imaging and cancer photodynamic therapy

The mitochondrial targeting and viscosity-sensitive near-infrared fluorescence probe TQS-OH was an aggregation induced emission luminogen constructed by regulating the receptor structure and hydroxylating its terminal. TQS-OH presented more than 27.35-fold fluorescence enhancement at the maximum emission peak when the viscosity level increased from 0.49 to 1048 cP. It also appeared excellent reactive oxygen species production ability under white light irradiation and appeared strong photodynamic therapied effect on HepG2 cells. In addition, cellular co-location analysis implied that TQS-OH had accurate mitochondrial targeting ability, with co-location coefficient up to 0.95 in human hepatocellular carcinoma HepG2 cells and it also successfully achieved fatty liver imaging. Meanwhile, we found that TQS-OH induced cancer cell apoptosis by activating mitochondrial apoptosis pathway. Furthermore, TQS-OH ultimately has implemented the tumor photodynamic therapy with high efficiency in vivo, with a tumor inhibition rate as high as 50.77%. The above results made it a promising aggregation induced emission material for the diagnosis of fatty liver and tumor phototherapy.

D–A Conjugated Organic Polymers as Nonhomogeneous Photocatalysts for PET-RAFT Polymerization

D–A conjugated organic polymer (COP) photocatalysts are a very promising photocatalytic material because of their tunable structure at the molecular level and diverse species. D–A conjugated organic polymers composed of relatively weak donor units and strong acceptor units are more favorable for photogenerated charge migration and thus exhibit better photocatalytic activity. Herein, a series of D–A conjugated organic polymers were constructed by introducing CN-absorbing groups to the benzene ring using 1,3,5-triethynylbenzene as the donor unit and the benzene ring as the acceptor unit to catalyze the reversible addition–fragmentation chain transfer (RAFT) polymerization of methyl methacrylate under white light irradiation, and the resulting polymers had controlled molecular weight and narrow molecular weight distribution. The effect of increasing the number of CN groups on the photogenerated charge migration ability of the catalyst and the RAFT polymerization rate was investigated by both experiments and theoretical calculation to reveal the conformational relationship between the polymer structure and the photocatalytic RAFT polymerization rate. It is proved that D–A conjugated organic polymers composed of relatively weak donor units and strong acceptor units are more favorable for photogenerated charge migration and thus exhibit better photocatalytic activity.

Synthesis of a Heavy-Atom-Free BODIPY and its Photooxygenation of 1-Naphthol to 1,4-Naphthoquinone

AbstractBy using 1,5,6,7-dihydro-4H-indol-4-one, a carbonyl group was introduced onto a BODIPY photosensitizer. The resulting heavy-atom-free BODIPY is a highly effective producer of singlet oxygen with a calculated quantum yield (ΦΔ) of 0.68, compared with that of methylene blue (ΦΔ = 0.57). Photooxygenation of 1-naphthol to 1,4-naphthoquinone was achieved by using this heavy-atom-free BODIPY catalyst in the presence of white-light irradiation under air atmosphere. Our work demonstrated a practical example of the design of a heavy-atom-free BODIPY, capable of efficient singlet-oxygen generation, with a potential in photocatalysis.

The First Report of In Vitro Antifungal and Antibiofilm Photodynamic Activity of Tetra-Cationic Porphyrins Containing Pt(II) Complexes against Candida albicans for Onychomycosis Treatment.

Onychomycosis is a prevalent nail fungal infection, and Candida albicans is one of the most common microorganisms associated with it. One alternative therapy to the conventional treatment of onychomycosis is antimicrobial photoinactivation. This study aimed to evaluate for the first time the in vitro activity of cationic porphyrins with platinum(II) complexes 4PtTPyP and 3PtTPyP against C. albicans. The minimum inhibitory concentration of porphyrins and reactive oxygen species was evaluated by broth microdilution. The yeast eradication time was evaluated using a time-kill assay, and a checkerboard assay assessed the synergism in combination with commercial treatments. In vitro biofilm formation and destruction were observed using the crystal violet technique. The morphology of the samples was evaluated by atomic force microscopy, and the MTT technique was used to evaluate the cytotoxicity of the studied porphyrins in keratinocyte and fibroblast cell lines. The porphyrin 3PtTPyP showed excellent in vitro antifungal activity against the tested C. albicans strains. After white-light irradiation, 3PtTPyP eradicated fungal growth in 30 and 60 min. The possible mechanism of action was mixed by ROS generation, and the combined treatment with commercial drugs was indifferent. The 3PtTPyP significantly reduced the preformed biofilm in vitro. Lastly, the atomic force microscopy showed cellular damage in the tested samples, and 3PtTPyP did not show cytotoxicity against the tested cell lines. We conclude that 3PtTPyP is an excellent photosensitizer with promising in vitro results against C. albicans strains.

Near-Infrared Emissive Cascaded Artificial Light-Harvesting System with Enhanced Antibacterial Efficiency.

Combination of platinum(II) metallacycles and photodynamic inactivation presents a promising antibacterial strategy. Herein, a cascaded artificial light-capturing system is developed in which an aggregation-induced emission-active platinum(II) metallacycle (PtTPEM) is utilized as the antenna, sulforhodamine 101 (SR101) as a key conveyor, and the near-infrared emissive photosensitizer Chlorin-e6 (Ce6) as the final energy acceptor. The well-dispersed Ce6 in the proximity of energy donors not only avoids self-quenching in the physiological environment but also contributes to energy transfer from donor to acceptor, thereby significantly improving the 1 O2 generation ability of the light-harvesting system under white light irradiation. By integrating the platinum(II) metallacycle and 1 O2 , a more efficient synergistic antibacterial effect is achieved at low concentrations, along with a significant decrease in dark toxicity caused by PtTPEM.

De novo design of highly efficient type-I photosensitizer based on π-conjugated oligomer for photodynamic eradication of multidrug-resistant bacterial infections

Traditional photosensitizers show limited singlet oxygen generation in hypoxic infection lesions, which greatly suppress their performance in antibacterial therapy. Meanwhile, there still is lack of feasible design strategy for developing hypoxia-overcoming photosensitizers agents. Herein, radical generation of π-conjugated small molecules is efficiently manipulated by an individual selenium (Se) substituent. With this strategy, the first proof-of-concept study of a Se-anchored oligo (thienyl ethynylene) (OT-Se) with high-performance superoxide radical (O2•−) and hydroxyl radical (•OH) generation capability is present, and achieves efficient antibacterial activities towards the clinically extracted multidrug-resistant bacteria methicillin-resistant S. aureus (MRSA) and carbapenem-resistant E. coli (CREC) at sub-micromolar concentration under a low white light irradiation (30 mW/cm2). The water-dispersible OT-Se shows a good bacteria-anchoring capability, biocompatibility, and complete elimination of multidrug-resistant bacteria wound infection in vivo. This work offers a strategy to boost type-I photodynamic therapy (PDT) performance for efficient antibacterial treatments, advancing the development of antibacterial agents.

Photocatalytic degradation study of methylene blue using carbon quantum dots synthesized from coconut husk

In this work, a facile and one-step hydrothermal method has been followed for the synthesis of undoped carbon quantum dots (UCQDs) and N-doped carbon quantum dots (NCQDs) from naturally available coconut husk. Coconut husk is a biowaste and abundant in nature, and hence its reusability is a topic of interest. We have investigated the optical properties and photocatalytic behaviour towards methylene blue dye (MB) degradation of CQDs derived from coconut husk under white light irradiation. Also, the photocatalytic behaviour in the different pH of MB dye is studied. Our study revealed that NCQDs perform as a better photocatalyst that could degrade 94% of MB dye within 150 min and show uniform performance in the pH range from 3 to 10.

Decoration of rutile TiO2 nanorod film with g-C3N4/SrTiO3 for efficient photoelectrochemical cathodic protection

A highly efficient g-C3N4/SrTiO3 co-decorated rutile TiO2 nanorod composite film photoanode was fabricated on a conductive glass substrate by a three-step synthesis process involving hydrothermal reactions and chemical vapor deposition. The g-C3N4/SrTiO3/TiO2 composite film with an appropriate cascade energy band structure showed greatly improved visible light absorption and exhibited 4.5 times higher photocurrent density than the undecorated TiO2 film, resulting from its higher separation and transfer efficiency of the photogenerated electron-hole pairs. Under the white light irradiation, the composite film photoanode made the potential of the coupled 403 stainless steel in a 0.5 M NaCl solution decrease by 680 mV from its free corrosion potential, showing a significantly enhanced photoelectrochemical cathodic protection effect.

Efficient NIR-II Type-I AIE Photosensitizer for Mitochondria-Targeted Photodynamic Therapy through Synergistic Apoptosis-Ferroptosis.

Hypoxia, the hallmark of malignant tumors, has been recognized as a major obstacle for photodynamic therapy (PDT). Precisely targeting cancer cells in intricate biological scenarios by a hypoxia-resistant photosensitizer (PS) is the cornerstone to conquer the inevitable tumor recurrence and metastasis. Herein, we describe an organic NIR-II PS (TPEQM-DMA) possessing potent type-I phototherapeutic efficacy to overcome the intrinsic pitfalls of PDT in combating hypoxic tumors. TPEQM-DMA exhibited prominent NIR-II emission (>1000 nm) with an aggregation-induced emission feature and efficiently produced superoxide anion and hydroxyl radical in the aggregate state under white light irradiation exclusively through a low-O2-dependent type-I photochemical process. The suitable cationic nature assisted TPEQM-DMA to accumulate in cancerous mitochondria. Meanwhile, the PDT of TPEQM-DMA impaired the cellular redox homeostasis, led to the mitochondrial dysfunction, and raised the level of lethal peroxidized lipids, which induced cellular apoptosis and ferroptosis. This synergistic cell death modality enabled TPEQM-DMA to suppress the growth of cancer cells, multicellular tumor spheroids, and tumors. To improve the pharmacological properties of TPEQM-DMA, TPEQM-DMA nanoparticles were prepared by encapsulation of polymer. In vivo experiments proved the appealing NIR-II fluorescence imaging-guided PDT effect of TPEQM-DMA nanoparticles for tumors.

Development of Sulfonamide‐Functionalized Charge‐Reversal AIE Photosensitizers for Precise Photodynamic Therapy in the Acidic Tumor Microenvironment

AbstractTumor‐targeted photodynamic therapy (PDT) is desirable as it can achieve efficient killing of tumor cells with no or less harm to normal cells. Herein, a facile molecular engineering strategy is developed for photosensitizers (PSs) with aggregation induced emission (AIE) characteristics and responsive properties to the acidic tumor microenvironment (TME). By the marriage of pH‐sensitive sulfonamide moieties with AIE PSs, two near‐infrared AIE luminogens called DBP‐SPy and DBP‐SPh are designed and synthesized. Both luminogens can form negatively charged nanoaggregates in the aqueous medium at physiological pH. The DBP‐SPy nanoaggregates undergo surface charge conversion to become positive at pH close to the signature pH of TME, while DBP‐SPh nanoaggregates show no such property. The endowed response to acidic TME enables the enhanced cellular uptake of DBP‐SPy at pH = 6.8. By contrast, its cellular uptake is much sacrificed at pH 7.4. As a result, under white light irradiation, DBP‐SPy nanoaggregates demonstrate a considerable photodynamic therapeutic effect on cancer cells in vitro and excellent tumor growth inhibition in vivo. Hence, this study not only provides an acidic TME‐responsive AIE PS for precise PDT, but also inspires new design strategies for AIE‐based theragnostic systems with targeting characteristics.

Light Induced Synthesis of Ag Nanorods for Potential Application as Optical Filter Tailored to Visible Domain

Monodispersed Ag nanorods were synthesized using a one-pot synthesis method. These Ag nanorods normally manifest dual surface plasmon resonance (SPR) peaks. This work presents a study of the variation of SPR peaks with variation in the shape of Ag nanorods. Shape variation was achieved through the degradation of a shape-controlling agent (PVP in this work) under white light irradiance with silica passivation to halt further shape variations. This paper also reports the growth &amp; characterization of thin films of the synthesized rod-shaped silver nanoparticles on glass slides along with studies on band pass filter characteristics of the as-synthesized nanoparticles.