Double Network Hydrogels Research Articles

Preparation and application of organic hydrogels incorporating polyacrylamide/sodium alginate/DMSO for enhanced anti-drying, anti-freezing, and self-healing properties

The double-network hydrogel comprises two asymmetrically structured cross-linked networks, demonstrating exceptional mechanical properties and possessing significant potential for application in the field of flexible sensors. However, conventional hydrogels primarily disperse in water as a medium and continuously lose moisture in natural environments, rendering them incapable of retaining hydration over extended periods and unsuitable for utilization under low-temperature conditions. In this study, we devised an organic hydrogel based on polyacrylamide (PAM), sodium alginate (SA), and dimethyl sulfoxide (DMSO). Through hydrogen bonding interactions among DMSO molecules, polyacrylamide, and sodium alginate, this organic hydrogel not only exhibits anti-drying and anti-freezing properties but also demonstrates self-healing characteristics. Moreover, the organic hydrogel showcases remarkable mechanical properties and conductivity capabilities that render it suitable for constructing flexible strain sensors to monitor human movements such as finger bending, elbow flexion, knee joint bending, and ankle extension. Additionally, the sensor exhibits excellent stability and durability.

Preparation of a chitosan/polyvinyl alcohol-based dual-network hydrogel for use as a potential wound-healing material for the sustainable release of drugs

Treating chronic wounds poses significant challenges in clinical medicine due to bacterial infection, reactive oxygen species (ROS) accumulation, and excessive inflammation. This study aimed to address these issues by developing a wound dressing with antibacterial, antioxidant, and anti-inflammatory properties. Chitosan was functionally modified with acrolein to covalently bind to epigallocatechin gallate (EGCG), enabling a high EGCG load. Subsequently, polyvinyl alcohol (PVA) and EGCG-modified chitosan were crosslinked to prepare a new double-network hydrogel with added cysteine (CSAEC/P50). CSAEC/P50 demonstrated optimal mechanical properties (low swelling rate, high water retention, and optimal flexibility), low hemolysis, high coagulation properties, and antibacterial and antioxidant activities. Cell scratch tests indicated that CSAEC/P50 can promote NIH3T3 cell migration. Immunofluorescence results showed that CSAEC/P50 promoted the transformation of proinflammatory M1 macrophages to anti-inflammatory M2 macrophages. These findings suggest that CSAEC/P50 has significant potential for use in wound dressing applications.

Exploring performance and mechanism of modified metal-organic frameworks in calcium alginate/polyvinyl alcohol double-network hydrogels for effective dye wastewater treatment

To address the growing problem of dye wastewater pollution, a novel MOFs adsorbent calcium alginate/polyvinyl alcohol@UiO-66 was developed using environmentally friendly polymers, sodium alginate and polyvinyl alcohol creating gel spheres with a double-network structure through cross-linking. UiO-66 metal-organic frameworks are then grown onto the gel spheres, resulting in the final CA/PVA@UiO-66 adsorbent. This adsorbent boasts a high surface area (17.4 m2/g) and a mesoporous-nested microporous structure. It effectively removes MB from water, the actual maximum adsorption capacity was measured at 275.8 mg/g, which surpasses most existing adsorbents. Remarkably, the adsorbent retains 93.9 % of its initial capacity even after 10 reuse cycles. The adsorption process adhered to the Redlich-Peterson model and the PFO model. The N2-Sorption isotherm, actual Methylene blue (MB) adsorption experiments, and model analysis further suggest that the adsorption process is a complex heterogeneous diffusion process involving simultaneous chemical and physical adsorption. Additionally, the adsorption process is endothermic, indicating that it can occur spontaneously at 298 K. Increasing the temperature promotes the forward progress of the adsorption reaction, thereby enhancing the adsorption capacity. The gel adsorbent exhibited excellent dye wastewater purification capabilities, coupled with commendable reusability.

Constructing Mg-phytic acid enhanced hydrogel patch with janus structure for antibacterial and angiogenic urethral repair

Due to bacteria in urine and inadequate blood supply, urethral defect repair faces great clinical difficulties. Inspired by the natural structure of the urethra, in this study, we designed a multifunctional hydrogel urethral patch with a Janus structure. The inner layer was a double-network hydrogel of polyvinyl alcohol/carboxymethyl chitosan (PVA/CMCS) enhanced by natural phytic acid (PA) and Mg2+ (Mg2+-PA/PVA/CMCS). The outer layer was composed of poly (L-lactic acid) (PLLA) nanofibers to form a hydrophobic barrier, coupling via a micelle layer to ensure interfacial bonding. The patch exhibited mechanical properties matching soft tissues, with maximum tensile strength and toughness of 1.69±0.13 MPa and 24.7±0.9 MJ/m3, respectively, under the strengthening effect of Mg2+-PA chelation. Therein, the 4 % Mg2+-PA/PVA/CMCS composite patch could maintain unilateral hydrophobicity for at least 14 days and demonstrated an antibacterial rate of 99.0 %±0.1 % against E. coli. In PBS, the patch could deliver Mg2+ for at least 7 days and stabilize the surrounding pH environment for up to 28 days. In vitro cell experiments indicated that the 4 % Mg2+-PA/PVA/CMCS composite patch could promote the human umbilical vein endothelial cell (HUVEC) proliferation and migration, with the angiogenic protein expression enhanced more than 1.2 times compared with the Control group. In conclusion, the patch constructed in this study may provide a new approach to clinical urethral injury repair.

Sweat-Enhanced Self-Adhesive Double-Network Hydrogel for Dynamic Skin Electrophysiology

Sweat-Enhanced Self-Adhesive Double-Network Hydrogel for Dynamic Skin Electrophysiology

Exploring Pyrazine-Based Organic Redox Couples for Enhanced Thermoelectric Performance in Wearable Energy Harvesters.

Thermoelectric generators (TEGs) based on thermogalvanic cells can convert low-temperature waste heat into electricity. Organic redox couples are well-suited for wearable devices due to their nontoxicity and the potential to enhance the ionic Seebeck coefficient through functional-group modifications. Pyrazine-based organic redox couples with different functional groups is comparatively analyzed through cyclic voltammetry under varying temperatures.The results reveal substantial differences in entropy changes with temperature and highlight 2,5-pyrazinedicarboxylic acid dihydrate (PDCA) as the optimal candidate.How the functional groups of the pyrazine compounds impact the ionic Seebeck coefficient is examined, by calculating the electrostatic potential based on density functional theory.To evaluate the thermoelectric properties, PDCA is integrated in different concentrations into a double-network hydrogel comprising poly(vinyl alcohol) and polyacrylamide. The resulting champion device exhibits an impressive ionic Seebeck coefficient (Si) of 2.99mV K-1, with ionic and thermal conductivities of ≈67.6 µS cm-1 and ≈0.49W m-1 K-1, respectively.Finally, a TEG is constructed by connecting 36 pieces of 20× 10-3 m PDCA-soaked hydrogel in series. It achieves a maximum power output of ≈0.28 µW under a temperature gradient of 28.3 °C and can power a small light-emitting diode. These findings highlight the significant potential of TEGs for wearable devices.

Highly efficient and sustainable polyacrylic acid-polyacrylamide double-network hydrogels prepared by cross-linking of waste residues for heavy metals ions removal

In this paper, an adsorbent composite called S-PEMR, which consists of electrolytic manganese residues (EMR)- silicate minerals-based polyacrylic acid-polyacrylamide double-network hydrogels, has been developed. The successful synthesis was confirmed by the characteristic peaks of COO, amide I, CO, -CH2, C-N group vibration in FTIR spectra as well as amorphous carbon in XRD patterns. This composite tackles the issue of harnessing EMR, which consists of layered silicate minerals and additional elements. These elements have potential value but are difficult to be effectively and safely utilized. It was observed that the adsorption process agreed with the quasi-secondary model and the Langmuir isotherm, the adsorption process is controlled by a chemisorption mechanism with the occurrence of electron sharing or electron transfer (establishment of covalent bonds) between the S-PEMR and the adsorbate. The S-PEMR was found to be recyclable up to four times. In the initial experiment, the concentrations of Ni, Cu, Cd, and Pb in a natural wastewater were recorded as 645.84, 906.21, 378.15, and 8.29 μg/L, respectively. The composites used in the study exhibited high removal efficiency for Ni (42.06 %), Cu (93.14 %), Cd (89.68 %), and Pb (77.02 %). The S-PEMR can be recycled up to four times with only a moderate reduction in adsorption performance. The removal mechanism primarily involved chelation or coordination, ion exchange, functional groups containing elements such as O and N, as well as the interaction of Si-O and Al-O with the heavy metal ions. This research establishes S-PEMR as a highly effective adsorbent for removing harmful contaminants from water.

A high temperature-resistant, strong, and self-healing double-network hydrogel for profile control in oil recovery

Hydrogels are widely used in profile control to plug high-permeability zones in oil recovery. In this study, a novel double-network (DN) hydrogel is developed for profile control. The two networks of the prepared hydrogel are polyacrylamide (PAAm) crosslinked by N,N’-Methylenebisacrylamide (MBAA) and konjac glucomannan (KGM) crosslinked by borax (B), respectively. The two networks are interconnected by their interpenetrating structures and hydrogen bonds. Based on the results of a series of evaluation experiments, the AAm/KGM DN hydrogels developed in this study exhibit a strong mechanical strength with their fracture stresses exceeding 0.137 MPa. Meanwhile, the AAm/KGM DN hydrogels can remain thermally stable after being heated at 130 °C for 24 h, indicating the good high-temperature resistance of the new sample. Moreover, the prepared AAm/KGM DN hydrogels present excellent self-healing performance due to the abundant hydrogen bonds in their structures, which helps form stable and long-term plugging in porous media. In addition, the pure PAAm hydrogel and the AAm/KGM DN hydrogel are sheared into two dispersed particle gel (DPG) suspensions to investigate their plugging performances. The results demonstrate that the AAm/KGM DN DPG can effectively plug a high-permeability sandpack with a plugging efficiency of 93.2 %, while the pure AAm DPG can only provide a much lower plugging efficiency of 60.5 %. The AAm/KGM DN hydrogel developed in this study, with its high mechanical strength, high-temperature resistance, and self-healing capability, offers a promising new candidate for profile control in oil recovery.

Ag quantum dots-doped poly (vinyl alcohol)/chitosan hydrogel coatings to prevent catheter-associated urinary tract infections

The prevention of catheter-associated urinary tract infections (CAUTIs) significantly impacts the reduction of morbidity and mortality associated with the use of indwelling urinary catheters. This study focused on developing an antibacterial double network hydrogel coating for latex urinary catheters, which incorporated Ag quantum dots (Ag QDs) in a polyvinyl alcohol (PVA)-chitosan (CS) double network hydrogel matrix. The PVA-CS-Ag QDs, referred to as the PCA hydrogel coating exhibited excellent mechanical and physiochemical properties with controlled release of Ag QDs. The antibacterial properties of the PCA hydrogel-coated urinary catheters were studied against both gram-negative Escherichia coli (E. coli, ATCC25922) and gram-positive Staphylococcus aureus (S. aureus, ATCC29213). The continuous release of CS oligomers and Ag QDs from the hydrogel coating contributed to the synergistic antibacterial and antiadhesion effects. Measurements of the Ag release rate revealed that even after 30 days, the concentration of Ag QDs from the PCA hydrogel-coated urinary catheters remained significantly higher than the effective antibacterial concentration of the total Ag (0.1 μg·L−1). These results indicated that the PCA hydrogel coating not only efficiently prevented bacteria attachment, but also exhibited long-term antibacterial activity, thereby inhibiting biofilm formation. Furthermore, the PCA hydrogel-coated urinary catheter demonstrated excellent biocompatibility and hemocompatibility. Overall, this novel PCA hydrogel-coated urinary catheter, with its exceptional antibacterial properties, holds great potential in reducing the incidence of CAUTIs.

Engineering living root with mechanical stimulation derived from reciprocating compression in a double network hydrogel as elastic soil

The root system actively reacts to mechanical stimuli in its environment, transmitting mechanical signals to optimize the utilization of environmental resources. While the mechanical impedance created by the growth medium serves as the primary source of stimulation for the roots, extensive research has focused on the roots' response to static mechanical stimulation. However, the impact of dynamic mechanical stimulation on root phenotype remains underexplored. In this study, we utilized a low acyl gellan gum/polyacrylamide (GG/PAM) double network elastic hydrogel as the growth medium for rapeseed. We constructed a mechanical device to investigate the effects of reciprocating extrusion stimulation on the growth of the rapeseed root system. After three weeks of mechanical stimulation, the root system exhibited a significant increase in lateral roots. This branching enhanced the roots' anchoring and penetration into the hydrogel, thereby improving the root system's adaptability to its environment. Our findings offer valuable data and insights into the effects of reciprocating mechanical stimulation on root growth, providing a new way for engineering root phenotype.

Polyacrylamide/sodium alginate double network hydrogel with easily repairable superhydrophobic surface for strain sensor resistant to fluid interference.

Constructing an easily repairable hydrophobic layer on the hydrogel surface that confers resistance to liquid interference remains a great challenge for hydrogel strain sensors. In this paper, superhydrophobic hydrogel sensors were prepared by driving hydrophobic organically modified silica (o-SiO2) nanoparticles to the surface of polyacrylamide/sodium alginate (PAM/SA) double network hydrogels by a weak ultrasonic field in o-SiO2/cyclohexane dispersion. The hydroxyl groups present on the surface of o-SiO2 are able to form hydrogen bonds with hydrogels, which in turn form a strong surface hydrophobic layer on its surface. The sensor exhibits superhydrophobic properties for different types of liquids, such as acids, salt solutions, etc., even in the stretched state. The broken o-SiO2 layers can be repaired by immersing in the o-SiO2/cyclohexane dispersion. The SA significantly improved the mechanical properties as well as the strain response sensitivity of the hydrogels. The hydrogel sensor is characterized by low hysteresis to strain, wide detection range (0-894%), low detection limit (1%), high sensitivity (GF=4.8), and good cyclic stability. The superhydrophobic surface allows the sensor to exhibit excellent anti-liquid interference. Salt solution droplets, prolonged contact with salt solution, and even short-term water immersion will not affect the sensor's response to strain. Moreover, repairing the broken hydrophobic layer enables the sensor to restore its resistance to liquid interference. The prepared hydrogel can be used for human motion monitoring in complex scenarios, including exercise sweating, rain, and short-time exposure to water.

Lanternarene-Based Self-Sorting Double-Network Hydrogels for Flexible Strain Sensors.

Conductive flexible hydrogels have attracted immense attentions recently due to their wide applications in wearable sensors. However, the poor mechanical properties of most conductive polymer limit their utilizations. Herein, a double network hydrogel is fabricated via a self-sorting process with cationic polyacrylamide as the first flexible network and the lantern[33]arene-based hydrogen organic framework nanofibers as the second rigid network. This hydrogel is endowed with good conductivity (0.25 S m-1) and mechanical properties, such as large Young's modulus (31.9MPa), fracture elongation (487%) and toughness (6.97MJ m-3). The stretchability of this hydrogel is greatly improved after the kirigami cutting, which makes it can be used as flexible strain sensor for monitoring human motions, such as bending of fingers, wrist and elbows. This study not only provides a valuable strategy for the construction of double network hydrogels by lanternarene, but also expands the application of the macrocycle hydrogels to flexible electronics.

A chemically defined, mechanically tunable, and bioactive hyaluronic acid/alginate double-network hydrogel for liver cancer organoid construction

Liver cancer organoids replicate the pathophysiology of primary tumors, making them ideal for drug screening and efficacy evaluation. However, their growth in complex, variable, animal-derived matrices hinders practical application. Here, we designed an easily accessible, chemically defined, biocompatible double-network hydrogel (HADR) using methacrylated hyaluronic acid (HAMA), sodium alginate (SA), methacrylated dopamine (DMA), and c(RGDFC) for liver cancer organoid culture. By optimizing critical extracellular matrix (ECM) parameters, the HADR hydrogel achieves compatibility with the physiological mechanics of the human liver and fosters the adhesion and proliferation of multiple cell types. In vitro drug efficacy tests showed that HepG2 cell line-derived liver cancer organoids exhibited higher IC50 values than 2D cultures, indicating greater drug resistance. Subcutaneous tumor models in nude mice revealed that HADR hydrogels created a microenvironment for HepG2 cells mirroring the natural tumor ECM, leading to increased tumor volume, denser cell arrangement, and concurrent microvascular development. In vivo drug efficacy evaluations indicated that DOX treatment downregulated Ki-67 and MMP-9 expression, inhibiting HepG2 cell proliferation, invasion, and metastasis. These findings demonstrate the potential of HADR hydrogels for liver cancer organoid culture, offering new strategies for personalized drug screening and efficacy evaluation.

V2CTx MXene-derived porphyrin-based MOF modified with ZIF-67 as an ultra-stretchable and deformable double-network hydrogel for room temperature detection of dimethylamine

Stretchable and self-adhesive chemical sensors are highly appealing for wearable applications in health and environmental monitoring. Here, for the first time, we report V2CTx MXene-derived Porphyrin-based MOF (V-PMOF) modified with Zeolite imidazole framework-67 (ZIF) for the room temperature detection of dimethylamine. V-PMOF is synthesized from V2CTx MXene using tetrakis(4-carboxyphenyl)porphyrin (TCPP) as a ligand via a solvothermal route. Thereafter, an optimized wt% ratio (1:1) of ZIF-67 and V-PMOF crosslinked by PVA/polypyrrole (Ppy) is put for lyophilisation which yields the V-PMOF@ZIF-67 double-network (DN) hydrogel. Detailed morphological assessment reveals dodecahedron shaped ZIF-67 particles are evenly distributed on the V-PMOF sheets which are encapsulated in the polymer matrix. This three-dimensional polymeric structure of hydrogel largely enhances the active sites on the surface with abundant oxygen vacancies. The sensor exhibits a dynamic range of 1 ppm to 13 ppm with a low limit of detection (LOD = 3 s/σ) of 902 ppb towards dimethylamine detection. Further, quick response/recovery times (3 s/7s) are observed along with high robustness tosignificant mechanical deformation, including twist (270°), large-range bending, and upto 500 % strain without affecting the sensing performance. The remarkable sensitivity is accredited to the abundance of O2 functional groups in polymer chains and the formation of schottky heterojunction between V-PMOF and ZIF-67, facilitating charge transfer from the heterostructure to dimethylamine during sensing. In addition, the self-adhesive hydrogel based sensor shows outstanding selectivity against other typical volatile organic compounds (VOCs) such acetone, ethanol, ammonia, trimethylamine, aniline, and methanol. In overall, this work provides insight into designing extremely flexible sensitive dimethylamine gas sensor as innovative material.

MXene and cellulose nanofibers reinforced hydrogel with high strength and photothermal self-healing performances for marine antifouling

Biological fouling is a considerable threat to the marine industry because attached microcontaminants and microorganisms inflict serious damage on marine installations and aquacultures. Although there has been tremendous effort in researching marine antifouling, it is yet challenging to develop a long-term and consistent antifouling strategy and materials. Here, polyhexamethylene-biguanide (PHMB) and MXene are introduced into the carboxylated cellulose nanofibers (CNF) reinforced polyvinyl alcohol (PVA) hydrogel to obtain a self-healing and ultra-high toughness antifouling hydrogel. The as-prepared double network (DN) hydrogels have extremely high toughness (16,050 kJ/m3), superior anti-protein adhesion (100 %) and anti-algal adhesion (100 %), exceptional antibacterial activity (99.97 %), and remarkable photothermal self-healing capability. Furthermore, the DN hydrogel provide outstanding antifouling performance for at least six months in the actual marine field. This work provides an effective and feasible strategy to prevent marine biofouling and also initiates new approaches to the application of hydrogel.

Influence of cellulose on the properties of physically cross-linked poly(vinyl alcohol)/Agar double network hydrogels and investigation of multifunctional flexible sensors

With the slogan "double carbon target" coming into the public's view, green, healthy, non-toxic and harmless hydrogel flexible sensors have become one of the research subjects of many staff. But most hydrogels need a crosslinking agent to complete polymerization. In this work, a PVA (poly (vinyl alcohol))/Agar hydrogel material was designed to form three-dimensional reticulated composite hydrogels with a variety of cellulose, and more green and healthy citric acid was used instead of PVA crosslinker to promote hydrogel polymerization. Through the test of four kinds of cellulose, it was found that PVA/ HPMC ( (Hydroxypropyl)methyl cellulose)/Agar hydrogel has the most outstanding performance, its mechanical property is 1.77MPa, its elongation at break can reach 766%, and it has good recovery performance, fatigue resistance and good adhesion. After it is applied to the flexible hydrogel sensor, its gauge factor value is as high as 5.94 under the strain of more than 200%. When simulating human skin and detecting human motion, the electrical signal changes sensitively and repeatedly, and has a good response when testing temperature and humidity. PVA/HPMC/Agar hydrogel provides a more healthy solution for flexible electronic devices.

Polyphenol-Mediated Adhesive and Anti-Inflammatory Double-Network Hydrogels for Repairing Postoperative Intervertebral Disc Defects.

Hydrogels have garnered tremendous attention for their applications in the repair of intervertebral disk (IVD) degeneration and postoperative IVD defects. However, it is still challenging to develop a hydrogel fulfilling the requirements for high mechanical properties, adhesive capability, biocompatibility, antibacterial properties, and anti-inflammatory performance. Herein, we report a multifunctional double-network (DN) hydrogel composed of physically cross-linked carboxymethyl chitosan (CMCS) and tannic acid (TA) networks as well as chemically cross-linked acrylamide (AM) networks, which integrates the properties of high strength, adhesion, biocompatibility, antimicrobial activity, and anti-inflammation for the repair of postoperative IVD defects. The treatment with CMCS/TA/PAM DN hydrogels can significantly decrease the levels of inflammatory cytokines and degeneration-related factors and upregulated collagen type II alpha 1. In addition, the hydrogels can effectively seal the annulus fibrosus defect, prevent nucleus pulposus degeneration, retain IVD height, and restore the biomechanical properties of the disc to some extent. This polyphenol-mediated DN hydrogel is promising for sealing IVD defects and preventing herniation after lumbar discectomy.

Preparation of accelerated-wound-healing lignin/dopamine-based nano-Fe3O4 hydrogels in sensing

Flexible conductive hydrogels hold great promise for applications in motion and medical detection. It is difficult to produce conductive hydrogel epidermal sensors in wearable hydrogels with dependable adhesion, sensing, and wound-healing properties. Nano-Fe3O4 was used as physical cross-linking points in the polyacrylamide/polyvinyl alcohol double network (PP) to increase the strain capacity of the hydrogel. The conductive lignin-dopamine (LD) was immobilized on the surface of Fe3O4 particles, and the LD-coated Fe3O4 was then incorporated into the double network hydrogel to create the PP/LD/Fe3O4 hydrogel. This work was done to look into the possibility of using Fe3O4 hydrogels as flexible strain sensors. The addition of LD/Fe3O4 caused the composite hydrogel to strain up to 124 %, with a modulus of elasticity of 21,308 Pa and electrical conductivity as high as 2.3 S•m−1 following the introduction of LD/Fe3O4. Moreover, the PP/LD/Fe3O4 hydrogel's adhesive qualities offered adequate antimicrobial properties and promoted wound healing. These results indicate that the developed electricity-responsive and tissue-adhesive hydrogel dressing offers a candidate to serve as a tissue sealant for wound healing.

Adjacent Fe-Pt atomic site synergistically boosting wearable biosensor performance in sweat analysis

Wearable electrochemical sensors have enormous potential in real-time and continuous monitoring of an individual’s physiological and biological state. In electrocatalysis, single-atom catalysts (SACs) with Fe-N4 active centers are attracting interest for their nearly complete metal utilization rate and unique unsaturated coordination configuration. Yet, their reliance on a single active site leads to a fixed adsorption mode for oxygen intermediates such as OH, greatly constraining design flexibility and catalytic performance. This study explores the synergistic effects between Fe-N4 and Pt-N4 active sites and their impact on the electrocatalytic activity towards uric acid (UA) and dopamine (DA). Proximal Pt-N4 atoms facilitate the activation of OH species on the Fe-N4 site and modulate the rehybridization of Fe d orbitals, thereby enhancing the adsorption of oxygen intermediates. This mechanism accelerates the overall electrocatalytic process for both UA and DA. Moreover, a non-swelling double network hydrogel is designed by combining chitosan with the P(AA-MEA)-Fe network. As a practical application, the non-swelling hydrogel channel, when combined with FeN4/PtN4 catalyst, successfully achieves real-time on-site detection of skin sweat biomarkers.

Quantification of morphine in exhaled breath condensate using a double network polymeric hybrid hydrogel functionalized with AuNPs

BackgroundMorphine serves as a foundation for creating other opioid derivatives, such as hydro/oxymorphine and heroin, which possess enhanced pain-relieving properties but are also prone to addiction and abuse. In cases of morphine overdose, it not only affects multiple immune functions but can also cause severe health complications. Given these concerns and the widespread use of morphine, it is crucial to develop efficient, uncomplicated, and precise methods for accurately detecting morphine in various biological and pharmaceutical samples.ResultsIn this investigation, a novel gold nanoparticle (AuNPs)-based double network hydrogel (DNH) nanoprobe has been fabricated for sensitive quantification of morphine in exhaled breath condensate samples. For that, gelatin/agarose DNH was fabricated through a one-step heating-cooling method in the presence of AuNPs, providing not only chemical stability but also prevent the AuNPs aggregation during synthesis process. In this method, the absorbance intensity of the nanoprobe gradually decreased with increasing morphine concentration due to the interaction morphine with AuNPs surface plasmon. The aggregation of AuNPs by addition of morphine was verified by UV-Vis spectrophotometry. The sensor displayed high sensitivity with detection limit of 0.006 µg.mL-1 in the linear range from 0.01 to 1.0 µg.mL-1. A reliable performance was attained for the spectrophotometric method for determination of morphine in the real samples.