Smart plasmonic hydrogels based on gold and silver nanoparticles for biosensing application

Temperature and light dual-responsive hydrogels for anti-inflammation and wound repair monitoring

Wound healing is a complex and dynamic biological process that requires meticulous management to ensure optimal outcomes. Traditional wound dressings, such as gauze and bandages, although commonly used, often fall short in their frequent need for replacement, lack of real-time monitoring and absence of anti-inflammatory and antibacterial properties, which can lead to increased risk of infection and delayed healing. Here, we address these limitations by introducing an innovative hydrogel dressing, named PHDNN6, to combine wireless Bluetooth temperature monitoring and light-triggered nitric oxide (NO) release to enhance wound healing and management. The PHDNN6 hydrogel is based on a poly(N-isopropylacrylamide) (PNIPAM) matrix, integrated with methacrylated and dopamine-grafted hyaluronic acid (HA-MA-DA), which allows the dressing to be highly responsive to changes in wound temperature, enabling continuous and real-time monitoring of the wound microenvironment wirelessly. Besides, PHDNN6 is embedded with photothermal polydopamine nanoparticles (PDA NPs) that are loaded with a NO donor, N,N'-di-sec-butyl-N,N'-dinitroso-1,4-phenylenediamine (BNN6). When exposed to near-infrared (NIR) laser irradiation, these PDA@BNN6 nanoparticles release NO to provide potent antibacterial and anti-inflammatory effects. The integration of continuous wireless temperature monitoring with NO release within a single hydrogel dressing represents a significant advancement in clinical wound care. This dual-functional platform not only provides real-time diagnostic capabilities but also offers therapeutic interventions to manage wound infections and promote tissue regeneration. Our research highlights the potential of PHDNN6 to revolutionize wound management by offering a comprehensive solution that addresses both the diagnostic and therapeutic needs in wound healing.

Impact of Plant Species on the Synthesis and Characterization of Biogenic Silver Nanoparticles: A Comparative Study of Brassica oleracea, Corylus avellana, and Camellia sinensis

The choice of plant species is crucial, as different plants provide unique biomolecules that influence nanoparticle characteristics. Biomolecules in plant extracts, such as proteins, amino acids, enzymes, polysaccharides, alkaloids, tannins, phenolics, saponins, terpenoids, and vitamins, act as stabilizing and reducing agents. This study explores the synthesis of silver nanoparticles (AgNPs) using leaf extracts from collard greens (Brassica oleracea var. acephala), hazelnut (Corylus avellana var. avellana), and green tea (Camellia sinensis). NPs were synthesized using silver nitrate (AgNO3) solution at two different molarities (1 mM and 5 mM) and characterized by UV-Vis spectroscopy, XRD, TEM, and FTIR. The Surface Plasmon Resonance (SPR) peaks appeared rapidly for hazelnut and green tea extracts, within 30 and 15 min, respectively, while collard greens extract failed to produce a distinct SPR peak. X-Ray Diffraction confirmed the formation of face-centered cubic silver. TEM analysis revealed high polydispersity and agglomeration in all samples, with particle size generally decreasing at higher AgNO3 concentrations. However, hazelnut extract showed a slight increase in size at higher molarity. Among all samples, green tea-derived AgNPs synthesized with 5 mM AgNO3 were the smallest and least polydisperse, highlighting the significant role of plant type in optimizing nanoparticle synthesis.

Nanoarchitectonics with cetrimonium bromide on metal nanoparticles for linker-free detection of toxic metal ions and catalytic degradation of 4-nitrophenol

Heavy metal ions and organic pollutants, such as 4-nitrophenol (4-NP), pose significant environmental and human health threats. Addressing these challenges necessitates using advanced nanoparticle-based systems capable of efficient detection and degradation. However, conventional approaches utilizing strong capping agents like cetrimonium bromide (CTAB) on nanoparticles lead to limitations due to the rigid nature of CTAB. This restricts its utility in heavy metal detection and 4-NP degradation, requiring additional surface modifications using linker molecules, thereby increasing process complexity and cost. To overcome these limitations, there is a critical need for the development of an easy-to-use, dual-functional, linker-free nanosystem capable of simultaneous detection of heavy metals and efficient degradation of 4-NP. For enabling linker-free/ligand-free detection of heavy metal ions and catalytic degradation of 4-NP, CTAB was engineered as a versatile capping agent on gold and silver nanoparticles. Various factors, including nanoparticle characteristics such as shape, size, metal composition, centrifugation, and NaOH amount, were investigated for their impact on the performance of CTAB-capped nanoparticles in heavy metal detection and 4-NP degradation. CTAB-Au nanospheres demonstrated limited heavy metal ion detection capability but exhibited remarkable efficiency in degrading 94.37% of 4-NP within 1 min. In contrast, silver nanospheres effectively detected Hg2+, Cu2+, and Fe3+ at concentrations as low as 1 ppm and degraded 90.78% of 4-NP within 30 min. Moreover, anisotropic gold nanorods (CTAB-AuNR1 and CTAB-AuNR2) showed promising sensing capabilities towards Cu2+, Cr3+, and Hg2+ at 0.5 OD, while efficiently degrading 4-NP within 5 min at 1 OD. This study emphasizes the importance of tailoring parameters of CTAB-capped nanoparticles for specific sensing and catalytic applications, offering potential solutions for environmental remediation and human health protection.

Light-Sheet Skew Ray-Based Microbubble Chemical Sensor for Pb2+ Measurements

A multimode fiber-based sensor is proposed and demonstrated for the detection of lead traces in contaminated water. The sensing mechanism involves using a light sheet to excite a specific group of skew rays that optimizes light absorption. The sensing region features an inline microbubble structure that funnels the skew rays into a tight ring, thereby intensifying the evanescent field. The sensitivity is further refined by incorporating gold nanoparticles, which amplify the evanescent field strength through localized surface plasmon resonance. The gold nanoparticles are functionalized with oxalic acid to improve specificity for lead ion detection. Experiment results demonstrated the significantly enhanced absorption sensitivity of the proposed sensing method for large center offsets, achieving a detection limit of 0.1305 ng/mL (the World Health Organization safety limit is 10 ng/mL) for concentrations ranging from 0.1 to 10 ng/mL.

Lysozyme-sensitive plasmonic hydrogel nanocomposite for colorimetric dry-eye inflammation biosensing

Detection of lysozyme levels in ocular fluids is considered crucial for diagnosing and monitoring various health and eye conditions, including dry-eye syndrome. Hydrogel-based nanocomposites have been demonstrated to be one of the most promising platforms for fast and accurate sensing of different biomolecules. In this work, hydrogel, electrospun nanofibers, and plasmonic nanoparticles are combined to fabricate a sensitive and easy-to-use biosensor for lysozyme. Poly(L-lactide-co-caprolactone) (PLCL) nanofibers were covered with silver nanoplates (AgNPls), providing a stable plasmonic platform, where a poly(N-isopropylacrylamide)-based (PNIPAAm) hydrogel layer allows mobility and good integration of the biomolecules. By integrating these components, the platform can also exhibit a colorimetric response to the concentration of lysozyme, allowing for easy and non-invasive monitoring. Quantitative biosensing operates on the principle of localized surface plasmon resonance (LSPR) induced by plasmonic nanoparticles. Chemical, structural, thermal, and optical characterizations were performed on each platform layer, and the platform's ability to detect lysozyme at concentrations relevant to those found in tears of patients with dry-eye syndrome and other related diseases was investigated by colorimetry and UV-Vis spectroscopy. This biosensor's sensitivity and rapid response time, alongside the easy detection by the naked eye, make it a promising tool for early diagnosis and treatment monitoring of eye diseases.

Recent advances towards point-of-care devices for fungal detection: Emphasizing the role of plasmonic nanomaterials in current and future technologies

Fungal infections are a significant global health problem, particularly affecting individuals with weakened immune systems. Moreover, as uncontrolled antibiotic and immunosuppressant use increases continuously, fungal infections have seen a dramatic increase, with some strains developing antibiotic resistance. Traditional approaches to identifying fungal strains often rely on morphological characteristics, thus owning limitations, such as struggles in identifying several strains or distinguishing between fungal strains with similar morphologies. This review explores the multifaceted impact of fungi infections on individuals, healthcare providers, and society, highlighting the often-underestimated economic burden and healthcare implications of these infections. In light of the serious constraints of traditional fungal identification methods, this review discusses the potential of plasmonic nanoparticle-based biosensors for fungal infection identification. These biosensors can enable rapid and precise fungal pathogen detection by exploiting several readout approaches, including various spectroscopic techniques, colorimetric and electrochemical assays, as well as lateral-flow immunoassay methods. Moreover, we report the remarkable impact of plasmonic Lab on a Chip technology and microfluidic devices, as they recently emerged as a class of advanced biosensors. Finally, we provide an overview of smartphone-based Point-of-Care devices and the associated technologies developed for detecting and identifying fungal pathogens.

Gold nanomakura: nanoarchitectonics and their photothermal response in association with carrageenan hydrogels

Photothermal conversion of light into heat energy is an intrinsic optical property of metal nanoparticles when irradiated using near-infrared radiation. However, the impact of size and shape on the photothermal behaviour of gold nanomakura particles possessing optical absorption within 600-700 nm as well as on incorporation in hydrogels is not well reported. In this study, nanomakura-shaped anisotropic gold nanoparticles (AuNMs) were synthesized via a surfactant-assisted seed-mediated protocol. Quaternary cationic surfactants having variable carbon tail length (n = 16, 14, 12) were used as capping for tuning the plasmon peak of gold nanomakura within a 600-700 nm wavelength. The aspect ratio as well as anisotropy of synthesized gold nanomakura can influence photothermal response upon near-infrared irradiation. The role of carbon tail length was evident via absorption peaks obtained from longitudinal surface plasmon resonance analysis at 670, 650, and 630 nm in CTAB-AuNM, MTAB-AuNM, and DTAB-AuNM, respectively. Furthermore, the impact of morphology and surrounding milieu of the synthesized nanomakuras on photothermal conversion is investigated owing to their retention of plasmonic stability. Interestingly, we found that photothermal conversion was exclusively assigned to morphological features (i.e., nanoparticles of higher aspect ratio showed higher temperature change and vice versa irrespective of the surfactant used). To enable biofunctionality and stability, we used kappa-carrageenan- (k-CG) based hydrogels for incorporating the nanomakuras and further assessed their photothermal response. Nanomakura particles in association with k-CG were also able to show photothermal conversion, depicting their ability to interact with light without hindrance. The CTAB-AuNM, MTAB-AuNM, and DTAB-AuNM after incorporation into hydrogel beads attained up to ≈17.2, ≈17.2, and ≈15.7 °C, respectively. On the other hand, gold nanorods after incorporation into k-CG did not yield much photothermal response as compared to that of AuNMs. The results showed a promising platform to utilize nanomakura particles along with kappa-carrageenan hydrogels for enabling usage on nanophotonic, photothermal, and bio-imaging applications.

Developing strategies to optimize the anchorage between electrospun nanofibers and hydrogels for multi-layered plasmonic biomaterials

Polycaprolactone (PCL), a recognized biopolymer, has emerged as a prominent choice for diverse biomedical endeavors due to its good mechanical properties, exceptional biocompatibility, and tunable properties. These attributes render PCL a suitable alternative biomaterial to use in biofabrication, especially the electrospinning technique, facilitating the production of nanofibers with varied dimensions and functionalities. However, the inherent hydrophobicity of PCL nanofibers can pose limitations. Conversely, acrylamide-based hydrogels, characterized by their interconnected porosity, significant water retention, and responsive behavior, present an ideal matrix for numerous biomedical applications. By merging these two materials, one can harness their collective strengths while potentially mitigating individual limitations. A robust interface and effective anchorage during the composite fabrication are pivotal for the optimal performance of the nanoplatforms. Nanoplatforms are subject to varying degrees of tension and physical alterations depending on their specific applications. This is particularly pertinent in the case of layered nanostructures, which require careful consideration to maintain structural stability and functional integrity in their intended applications. In this study, we delve into the influence of the fiber dimensions, orientation and surface modifications of the nanofibrous layer and the hydrogel layer's crosslinking density on their intralayer interface to determine the optimal approach. Comprehensive mechanical pull-out tests offer insights into the interfacial adhesion and anchorage between the layers. Notably, plasma treatment of the hydrophobic nanofibers and the stiffness of the hydrogel layer significantly enhance the mechanical effort required for fiber extraction from the hydrogels, indicating improved anchorage. Furthermore, biocompatibility assessments confirm the potential biomedical applications of the proposed nanoplatforms.

Antimicrobial, Antioxidant, and Anti-Inflammatory Nanoplatform for Effective Management of Infected Wounds

Burn wound healing continues to pose significant challenges due to excessive inflammation, the risk of infection, and impaired tissue regeneration. In this regard, an antibacterial, antioxidant, and anti-inflammatory nanocomposite (called HPA) that combines a nanosystem using hexachlorocyclotriphosphazene and the natural polyphenol of Phloretin with silver nanoparticles (AgNPs) is developed. HPA effectively disperses AgNPs to mitigate any toxicity caused by aggregation while also showing the pharmacological activities of Phloretin. During the initial stage of wound healing, HPA rapidly releases silver ions from its surface to suppress bacterial activity. Moreover, these nanoparticles are pH-sensitive and degrade efficiently in the acidic infection microenvironment, gradually releasing Phloretin. This sustained release of Phloretin helps scavenge overexpressed reactive oxygen species in the infected microenvironment area, thus reducing the upregulation of pro-inflammatory cytokines. The antibacterial activity, free radical clearance, and regulation of inflammatory factors of HPA through in vitro experiments are validated. Additionally, its effects using an infectious burn mouse model in vivo are evaluated. HPA is found to promote collagen deposition and epithelialization in the wound area. With its synergistic antibacterial, antioxidant, and anti-inflammatory activities, as well as favorable biocompatibilities, HPA shows great promise as a safe and effective multifunctional nanoplatform for burn injury wound dressings.

In Situ Synthesis of Gold Nanoparticles from Chitin Nanogels and Their Drug Release Response to Stimulation

In this study, gold nanoparticles (AuNPs) were synthesized in situ using chitin nanogels (CNGs) as templates to prepare composites (CNGs@AuNPs) with good photothermal properties, wherein their drug release properties in response to stimulation by near-infrared (NIR) light were investigated. AuNPs with particle sizes ranging from 2.5 nm to 90 nm were prepared by varying the reaction temperature and chloroauric acid concentration. The photothermal effect of different materials was probed by near-infrared light. Under 1 mg/mL of chloroauric acid at 120 °C, the prepared CNGs@AuNPs could increase the temperature by 32 °C within 10 min at a power of 2 W/cm2. The Adriamycin hydrochloride (DOX) was loaded into the CNGs@AuNPs to investigate their release behaviors under different pH values, temperatures, and near-infrared light stimulations. The results showed that CNGs@AuNPs were pH- and temperature-responsive, suggesting that low pH and high temperature could promote drug release. In addition, NIR light stimulation accelerated the drug release. Cellular experiments confirmed the synergistic effect of DOX-loaded CNGs@AuNPs on chemotherapy and photothermal therapy under NIR radiation.

Influence of conductive carbon and MnCo2O4 on morphological and electrical properties of hydrogels for electrochemical energy conversion

In this work, a strategy for one-stage synthesis of polymer composites based on PNIPAAm hydrogel was presented. Both conductive particles in the form of conductive carbon black (cCB) and MnCo2O4 (MCO) spinel particles were suspended in the three-dimensional structure of the hydrogel. The MCO particles in the resulting hydrogel composite acted as an electrocatalyst in the oxygen evolution reaction. Morphological studies confirmed that the added particles were incorporated and, in the case of a higher concentration of cCB particles, also bound to the surface of the structure of the hydrogel matrix. The produced composite materials were tested in terms of their electrical properties, showing that an increase in the concentration of conductive particles in the hydrogel structure translates into a lowering of the impedance modulus and an increase in the double-layer capacitance of the electrode. This, in turn, resulted in a higher catalytic activity of the electrode in the oxygen evolution reaction. The use of a hydrogel as a matrix to suspend the catalyst particles, and thus increase their availability through the electrolyte, seems to be an interesting and promising application approach.

A Review on Electroactive Polymer-Metal Composites: Development and Applications for Tissue Regeneration

Electroactive polymer-metal composites (EAPMCs) have gained significant attention in tissue engineering owing to their exceptional mechanical and electrical properties. EAPMCs develop by combining an electroactive polymer matrix and a conductive metal. The design considerations include choosing an appropriate metal that provides mechanical strength and electrical conductivity and selecting an electroactive polymer that displays biocompatibility and electrical responsiveness. Interface engineering and surface modification techniques are also crucial for enhancing the adhesion and biocompatibility of composites. The potential of EAPMC-based tissue engineering revolves around its ability to promote cellular responses, such as cell adhesion, proliferation, and differentiation, through electrical stimulation. The electrical properties of these composites can be used to mimic natural electrical signals within tissues and organs, thereby aiding tissue regeneration. Furthermore, the mechanical characteristics of the metallic components provide structural reinforcement and can be modified to align with the distinct demands of various tissues. EAPMCs have extraordinary potential as regenerative biomaterials owing to their ability to promote beneficial effects in numerous electrically responsive cells. This study emphasizes the characteristics and applications of EAPMCs in tissue engineering.

A Photocurable Polysaccharide-Based Hydrogel Delivery of Polydeoxyribonucleotide-Loaded Vectors for Wound Treatment

The wounds caused by war, accidents, and diseases require timely and effective treatment. Polysaccharides, as natural macromolecules, have good biocompatibility and unique functions, and are excellent substrates for constructing new wound dressings. Short-chain chitosan (SCS) has good water solubility and, importantly, retains a large number of active amino groups. We first introduce double bonds to SCS. This chitosan derivative can be entangled with sodium alginate (SA) through electrostatic interaction. The flowing sol can be applied to a wound with an irregular shape. Under the initiation of a photoinitiator, the internal double bonds are broken and cross-linked to form a gel. The prepared hydrogel wound dressing exhibited good antibacterial properties and can provide a microenvironment conducive to wound repair. A polydeoxyribonucleotide (PDRN) has been proven to have encouraging therapeutic effects for wound healing. PDRN can be condensed by branched polyethylenimine (PEI) to form a nucleic acid delivery system, which can be efficiently uptaken by cells. The cooperation of hydrogel and nucleic-acid-based therapy presented good results in a mouse full-thickness skin wound model.

Electrochemical Wearable Biosensors and Bioelectronic Devices Based on Hydrogels: Mechanical Properties and Electrochemical Behavior

Hydrogel-based wearable electrochemical biosensors (HWEBs) are emerging biomedical devices that have recently received immense interest. The exceptional properties of HWEBs include excellent biocompatibility with hydrophilic nature, high porosity, tailorable permeability, the capability of reliable and accurate detection of disease biomarkers, suitable device-human interface, facile adjustability, and stimuli responsive to the nanofiller materials. Although the biomimetic three-dimensional hydrogels can immobilize bioreceptors, such as enzymes and aptamers, without any loss in their activities. However, most HWEBs suffer from low mechanical strength and electrical conductivity. Many studies have been performed on emerging electroactive nanofillers, including biomacromolecules, carbon-based materials, and inorganic and organic nanomaterials, to tackle these issues. Non-conductive hydrogels and even conductive hydrogels may be modified by nanofillers, as well as redox species. All these modifications have led to the design and development of efficient nanocomposites as electrochemical biosensors. In this review, both conductive-based and non-conductive-based hydrogels derived from natural and synthetic polymers are systematically reviewed. The main synthesis methods and characterization techniques are addressed. The mechanical properties and electrochemical behavior of HWEBs are discussed in detail. Finally, the prospects and potential applications of HWEBs in biosensing, healthcare monitoring, and clinical diagnostics are highlighted.

Hydrogel-Based Biosensors for Effective Therapeutics

Nanotechnology and polymer engineering are navigating toward new developments to control and overcome complex problems. In the last few decades, polymer engineering has received researchers' attention and similarly, polymeric network-engineered structures have been vastly studied. Prior to therapeutic application, early and rapid detection analyses are critical. Therefore, developing hydrogel-based sensors to manage the acute expression of diseases and malignancies to devise therapeutic approaches demands advanced nanoengineering. However, nano-therapeutics have emerged as an alternative approach to tackling strenuous diseases. Similarly, sensing applications for multiple kinds of analytes in water-based environments and other media are gaining wide interest. It has also been observed that these functional roles can be used as alternative approaches to the detection of a wide range of biomolecules and pathogenic proteins. Moreover, hydrogels have emerged as a three-dimensional (3D) polymeric network that consists of hydrophilic natural or synthetic polymers with multidimensional dynamics. The resemblance of hydrogels to tissue structure makes them more unique to study inquisitively. Preceding studies have shown a vast spectrum of synthetic and natural polymer applications in the field of biotechnology and molecular diagnostics. This review explores recent studies on synthetic and natural polymers engineered hydrogel-based biosensors and their applications in multipurpose diagnostics and therapeutics. We review the latest studies on hydrogel-engineered biosensors, exclusively DNA-based and DNA hydrogel-fabricated biosensors.

Evolution of nanostructured skin patches towards multifunctional wearable platforms for biomedical applications

Recent advances in the field of skin patches have promoted the development of wearable and implantable bioelectronics for long-term, continuous healthcare management and targeted therapy. However, the design of electronic skin (e-skin) patches with stretchable components is still challenging and requires an in-depth understanding of the skin-attachable substrate layer, functional biomaterials and advanced self-powered electronics. In this comprehensive review, we present the evolution of skin patches from functional nanostructured materials to multi-functional and stimuli-responsive patches towards flexible substrates and emerging biomaterials for e-skin patches, including the material selection, structure design and promising applications. Stretchable sensors and self-powered e-skin patches are also discussed, ranging from electrical stimulation for clinical procedures to continuous health monitoring and integrated systems for comprehensive healthcare management. Moreover, an integrated energy harvester with bioelectronics enables the fabrication of self-powered electronic skin patches, which can effectively solve the energy supply and overcome the drawbacks induced by bulky battery-driven devices. However, to realize the full potential offered by these advancements, several challenges must be addressed for next-generation e-skin patches. Finally, future opportunities and positive outlooks are presented on the future directions of bioelectronics. It is believed that innovative material design, structure engineering, and in-depth study of fundamental principles can foster the rapid evolution of electronic skin patches, and eventually enable self-powered close-looped bioelectronic systems to benefit mankind.

Silver Nanoparticles Loaded on Chitosan-g-PVA Hydrogel for the Wound-Healing Applications

Silver nanoparticle composites have abundant biomedical applications due to their unique antibacterial properties. In the current work, green tea leaf extract was used as a natural reducing agent to synthesize AgNPs (AgNPs) using microwave irradiation technology. Furthermore, microwave irradiation has been used for the preparation of AgNPs/chitosan (Ch) grafted polyvinyl alcohol (PVA) hydrogel samples. To approve the accomplishment of AgNPs hydrogel polymer, UV-spectrum, TEM, and FT-IR spectrum analyses and the release of silver ions, actions were taken. The wound-healing ability of the prepared hydrogel samples was measured via both the in vitro (fibroblast cells) and the in vivo using rat models. It was found that chitosan-grafted polyvinyl alcohol, including AgNPs, exhibited excellent antibacterial activity against E. coli and S. aureus using the agar diffusion method. It can be said that microwave irradiation was successful in creating a hydrogel that contained silver nanoparticles. A wound that was still open was successfully treated with these composites.

Advances in the Design of Phenylboronic Acid-Based Glucose-Sensitive Hydrogels

Diabetes, characterized by an uncontrolled blood glucose level, is the main cause of blindness, heart attack, stroke, and lower limb amputation. Glucose-sensitive hydrogels able to release hypoglycemic drugs (such as insulin) as a response to the increase of the glucose level are of interest for researchers, considering the large number of diabetes patients in the world (537 million in 2021, reported by the International Diabetes Federation). Considering the current growth, it is estimated that, up to 2045, the number of people with diabetes will increase to 783 million. The present work reviews the recent developments on the hydrogels based on phenylboronic acid and its derivatives, with sensitivity to glucose, which can be suitable candidates for the design of insulin delivery systems. After a brief presentation of the dynamic covalent bonds, the design of glucose-responsive hydrogels, the mechanism by which the hypoglycemic drug release is achieved, and their self-healing capacity are presented and discussed. Finally, the conclusions and the main aspects that should be addressed in future research are shown.

Tuning Plasmonic Properties of Gold Nanoparticles by Employing Nanoscale DNA Hydrogel Scaffolds

Noble metals have always fascinated researchers due to their feasible and facile approach to plasmonics. Especially the extensive utilization of gold (Au) has been found in biomedical engineering, microelectronics, and catalysis. Surface plasmonic resonance (SPR) sensors are achievable by employing plasmonic nanoparticles. The past decades have seen colossal advancement in noble metal nanoparticle research. Surface plasmonic biosensors are advanced in terms of sensing accuracy and detection limit. Likewise, gold nanoparticles (AuNPs) have been widely used to develop distinct biosensors for molecular diagnosis. DNA nanotechnology facilitates advanced nanostructure having unique properties that contribute vastly to clinical therapeutics. The critical element for absolute control of materials at the nanoscale is the engineering of optical and plasmonic characteristics of the polymeric and metallic nanostructure. Correspondingly, AuNP's vivid intense color expressions are dependent on their size, shape, and compositions, which implies their strong influence on tuning the plasmonic properties. These plasmonic properties of AuNPs have vastly exerted the biosensing and molecular diagnosis applications without any hazardous effects. Here, we have designed nanoscale X-DNA-based Dgel scaffolds utilized for tuning the plasmonic properties of AuNPs. The DNA nanohydrogel (Dgel) scaffolds engineered with three different X-DNAs of distinct numbers of base pairs were applied. We have designed X-DNA base pair-controlled size-varied Dgel scaffolds and molar ratio-based nano assemblies to tune the plasmonic properties of AuNPs. The nanoscale DNA hydrogel's negatively charged scaffold facilitates quaternary ammonium ligand-modified positively charged AuNPs to flocculate around due to electrostatic charge attractions. Overall, our study demonstrates that by altering the DNA hydrogel scaffolds and the physical properties of the nanoscale hydrogel matrix, the SPR properties can be modulated. This approach could potentially benefit in monitoring diverse therapeutic biomolecules.