NIR-driven multifunctional PEC biosensor based on aptamer-modified PDA/MnO2 photoelectrode for bacterial detection and inactivation.

Sensitive detection and effective inactivation of bacteria are essential in preventing foodborne bacterial infection that poses a significant threat to human health. Herein, a near-infrared (NIR)-driven multifunctional photoelectrochemical (PEC) biosensor was constructed for detection and inactivation of S. aureus. Based on the covalent bonding between amine and carboxyl groups, carboxyl-functionalized SA31 aptamer was immobilized on the PDA/MnO2 photoelectrode. In the presence of S. aureus, SA31 aptamer can specifically capture S. aureus, causing the decrease of photocurrent signal owing to steric hindrance effect. Leveraging photocurrent-off signal, there existed a satisfied linear relationship between the photocurrent variation and the logarithm of S. aureus concentration, achieving a wide linear range from 10 to 107 CFU/mL with a low detection limit of 2.0 CFU/mL. Notably, PDA/MnO2 with peroxidase-like activity facilitated the catalytic oxidation of S. aureus with assistance of hydrogen peroxide (H2O2) to cause the inactivation of S. aureus. Desorption of inactivated S. aureus from the photoelectrode led to a recovery of photocurrent signal, enabling a "signal on" switch. Simultaneously, the excellent photothermal performance of the PDA/MnO2 converted light energy into heat energy under the irradiation of NIR light (808 nm, 1.5 W/cm2), triggering the synergistic antibacterial effect against S. aureus (97.36%). This work provides a novel strategy for fabricating the detection and inactivation of bacteria in practical applications.

Patterned Au@Ag nanoarrays with electrically stimulated laccase-mimicking activity for dual-mode detection of epinephrine.

Epinephrine (EP) is a crucial neurotransmitter in the central nervous system. However, an abnormal level of EP in biological fluids can lead to various diseases. Therefore, it is essential to rapidly and accurately detect EP content. Herein, electrically stimulated patterned Au@Ag nanoarrays with laccase-mimicking activity were designed for the dual-mode detection of EP concentration. The patterned Au@Ag nanoarrays exhibit excellent electrochemical properties and electrically stimulated laccase-mimicking activity. They provide sensitive electrochemical responses for detecting EP content. Simultaneously, the Au@Ag nanoarrays can catalyze the oxidation of EP, enabling its detection through a colorimetric process. This dual-mode approach achieves the detection of EP content over a wide linear range of 0.5-200 µM, with a low detection limit of 0.152 µM. Furthermore, the utility of these nanoarrays for sensing EP in human serum was evaluated. This work provides a convenient method using patterned nanozyme array for the visible, rapid and accurate detection of EP content. It provides the important implication for the development of portable and reliable on-site analytical instruments.

A Portable Integrated Electrochemical Sensing System for On-Site Nitrite Detection in Food.

Ensuring an appropriate nitrite level in food is essential to keep the body healthy. However, it still remains a huge challenge to offer a portable and low-cost on-site food nitrite analysis without any expensive equipment. Herein, a portable integrated electrochemical sensing system (IESS) is developed to achieve rapid on-site nitrite detection in food, which is composed of a low-cost disposable microfluidic electrochemical patch for few-shot nitrite detection, and a reusable smartphone-assisted electronic device based on self-designed circuit board for signal processing and wireless transmission. The electrochemical patch based on MXene-Ti3 C2 Tx /multiwalled carbon nanotubes-cyanocobalamin (MXene/MWCNTs-VB12 )-modified working electrode achieves high sensitivity of 10.533 µA mm-1 and low nitrite detection limit of 4.22 µm owing to strong electron transfer ability of hybrid MXene/MWCNTs conductive matrix and high nitrite selectivity of VB12 bionic enzyme-based ion-selective layer. Moreover, the portable IESS can rapidly collect pending testing samples through a microfluidic electrochemical patch within 1.0 s to conduct immediate nitrite analysis, and then wirelessly transmit data from a signal-processing electronic device to a smartphone via Bluetooth module. Consequently, this proposed portable IESS demonstrates rapid on-site nitrite analysis and wireless data transmission within one palm-sized electronic device, which would pave a new avenue in food safety and personal bespoke therapy.

A dual-modal ROS generator based on multifunctional PDA-MnO2@Ce6 nanozymes for synergistic chemo-photodynamic antibacterial therapy.

The rapid emergence of drug-resistant bacteria has attracted great attention to exploring advanced antibacterial methods. However, single-modal antibacterial therapy cannot easily eliminate drug-resistant bacteria completely due to its low efficacy. Therefore, it is essential to achieve multi-modal antibacterial therapy effectively. Herein, a dual-modal ROS generator was designed based on photosensitive PDA-MnO2@Ce6/liposome (PMCL) nanozymes for synergistic chemo-photodynamic therapy. PMCL nanozymes adhere to bacteria through liposome-membrane fusion. Meanwhile, PMCL catalyzes endogenous hydrogen peroxide (H2O2) to generate hydroxyl radicals (˙OH) and singlet oxygen (1O2) under laser irradiation. Furthermore, the photothermal effect can accelerate the generation of ROS. Based on dual-enzyme activities (mimicking peroxidase and catalase) and photodynamic properties, PMCL achieves powerful antibacterial efficacy and mature bacterial biofilm eradication. With the synergistic chemo-photodynamic effects, bacterial populations decrease by >99.76% against Gram-positive S. aureus and Gram-negative E. coli. Notably, the synergistic antibacterial properties of PMCL nanozymes are further explored using a mouse wound model of S. aureus infection. This work fabricated an efficient dual-modal ROS generator to kill bacteria, further providing a new strategy for treating wound infection.

Core-satellite nanoreactors based on cationic photosensitizer modified hollow CuS nanocage for ROS diffusion enhanced phototherapy of hypoxic tumor.

Photodynamic therapy (PDT) efficiency is directly affected by the reactive oxygen species (ROS) generated by photosensitizers. However, ROSs' ultrashort life span and limited diffusion distance restrict the PDT efficiency. Therefore, it is important to control the delivery strategy of photosensitizers for PDT treatment. Herein, the core-satellite nanoreactors were fabricated with oxygen generation and ROS diffusion properties. The hollow CuS encapsulating horseradish peroxidase (HRP) was combined with the cationic photosensitizers (PEI-Ce6). The unique photosensitizers delivery strategy makes the nanoreactors achieve ROS diffusion-enhanced PDT effect. First, HRP in "core" (HRP@CuS) can decompose hydrogen peroxide (H2O2) to O2, increasing O2 levels on the surface of the nanoreactor. Second, the Ce6 molecules covalent-linked with PEI are uniformly dispersed on the surface of CuS as a "satellite", avoiding Ce6 aggregation and causing more Ce6 molecules be activated to produce more 1O2. Due to the Ce6 was on the surface of the CuS nanocages, the generated ROS may ensure a larger diffusion range. Meanwhile, the inherently CuS nanocages exhibit photothermal and photoacoustic (PA) effect. The photothermal effect further enhances the ROS diffusion. Under the guidance of PA imaging, nanoreactors exhibit highly efficient hypoxic tumor ablation via photodynamic and photothermal effect. Overall, the core-satellite nanoreactors provide an effective strategy for tumor therapy, further promoting the research of photosensitizers delivery.

Electrothermal sterilization and self-powered real-time respiratory monitoring of reusable mask based on Ag micro-mesh films.

Since the COVID-19 pandemic outbreaks, the utilization of medical masks plays a critical role in reducing the infected risk. However, constructing multifunctional masks to achieve simultaneously self-sterilization, reusability, and respiratory monitoring capability remains still a huge challenge. Herein, a reusable Ag micro-mesh film-based mask is proposed, which enables the capabilities of electrothermal sterilization and self-powered real-time respiratory monitoring. Highly conductive Ag micro-mesh films prepared by continuous draw spinning method demonstrate excellent electrothermal performances for thermal sterilization and serve as working electrode to fabricate triboelectric nanogenerator (TENG) for real-time respiratory monitoring, respectively. Under a low driving voltage of 3.0 V, the surface temperature of Ag micro-mesh film enables a quick increase to over 60 °C within 30 s, which endows thermal sterilization against S. aureus with antibacterial efficiency of 95.58 % within 20 min to achieve the self-sterilization of medical masks. Furthermore, a self-powered alarm system based on the fabricated TENG as respiratory monitor is developed for real-time respiratory monitoring to render a timely treatment for patients in danger of tachypnea and apnea. Consequently, this work has paved a new and practical avenue to achieve reusable multifunctional masks with capabilities of electrothermal sterilization and real-time respiratory monitoring in clinical medicine.

Highly dispersive AuNCs/ChOx@ZIF-8/PEI nanocomplexes for fluorescent detection of cholesterol in human serum.

Gold nanoclusters (AuNCs) are widely used in the fluorescence detection of biomolecules in human serum due to their good fluorescence properties, low toxicity, and better biocompatibility. However, the weak fluorescence intensity of AuNCs limits the fluorescence detection of molecules within a wide concentration range. It is reported that coating AuNCs in ZIF-8 with adjustable pore size can effectively improve the fluorescence intensity of AuNCs and broaden the detection range. And the AuNCs wrapped in the gaps of ZIF-8 can prevent the fluorescence quenching caused by the aggregation of AuNCs. However, ZIF-8 has high crystallinity, poor dispersion, and easy deposition, which reduces the fluorescence stability of the detection system and affects the detection. Based on the above research, the highly hydrophilic polymer PEI was modified to the surface of ZIF-8, and a kind of nanocomposite material AuNCs/ChOx@ZIF-8/PEI was obtained by co-encapsulating AuNCs prepared with glutathione as a ligand and cholesterol oxidase (ChOx) into ZIF-8 modified with PEI. The composite material emits strong red light at 650 nm under the excitation of 395-nm light, and the system can sensitively detect cholesterol (Chol) in human serum. Compared with other materials, the PEI-modified composite has better solubility and stability, so the detection effect of Chol is better. Encapsulation of ChOx in the ZIF-8 shell can protect the enzyme and increase the local concentration of ChOx, thereby speeding up the reaction rate. Compared with free AuNCs/ChOx, the quenching rate of AuNCs/ChOx@ZIF-8/PEI system is doubled. Secondly, the addition of Fe2+ to the detection process results in higher quenching rate and detection sensitivity. The system can detect Chol in the concentration range 0.1-2.4 µM, with a detection limit of 0.073 µM. The determination is a fast and sensitive strategy. In addition, the practicability of this assay in the detection of Chol in human serum has been verified. Due to its selectivity and sensitivity, it has potential application value in clinical diagnosis.

Biocompatible BSA-Ag2S nanoparticles for photothermal therapy of cancer.

Photothermal therapy (PTT) induced by near-infrared (NIR) laser has attracted much attention for the innovation of tumor therapy, in which the photothermal agent with good biocompatibility and high efficiency is the prerequisite. Herein, the biocompatible bovine serum albumin (BSA) coated Ag2S nanoparticles (NPs) as photothermal agent were synthesized directly at mild temperature for PTT of cancer. The high photothermal conversion efficiency of the obtained Ag2S NPs with strong NIR absorption is about 18.89%, which make them ideal materials for photothermal agents. Furthermore, the Ag2S NPs can induce effective apoptosis of tumor cells exposed to an NIR laser (808 nm), realizing an effective PTT with excellent killing effect of tumor cells. This work provides a simple reproducible method to fabricate the water-soluble and biocompatible Ag2S NPs, which would provide new insights of designing new functional NPs for the PTT therapy of tumor.

Photothermal-enhanced peroxidase-like activity of CDs/PBNPs for the detection of Fe3+ and cholesterol in serum samples.

Carbon dots/Prussian blue nanoparticles (CDs/PBNPs) with fluorescence (FL) performance and peroxidase-like activity are synthesized by a simple two-step method. The FL of CDs/PBNPs can be effectively quenched by Fe3+. Fe3+ can accelerate the peroxidase-like activity of CDs/PBNPs. More excitingly, the peroxidase-like activity of CDs/PBNPs could be further enhanced due to the influence of the photothermal effect. Based on the FL property and enhanced peroxidase-like activity, a cascade strategy is proposed for detection of Fe3+ and free cholesterol. CD/PBNPs act as FL probe for detection of Fe3+. The enhanced peroxidase-like activity of CDs/PBNPs can also be used as colorimetric probe for the detection of free cholesterol. The detection ranges of Fe3+ and free cholesterol are 4-128 µM and 2-39 µM, and the corresponding limit of detections are 2.0 µM and 1.63 µM, respectively. The proposed strategy has been verified by the feasibility determination of Fe3+ and free cholesterol, suggesting its potential in the prediction of disease.

ZIF-67-derived Co3O4 hollow nanocage with efficient peroxidase mimicking characteristic for sensitive colorimetric biosensing of dopamine.

Co3O4 hollow nanocages (Co3O4 HNCs) were prepared by simple calcination with ZIF-67 as the precursor. Compared with ordinary nano-sized Co3O4, skeletal Co3O4 HNCs have a larger specific surface area and porosity, lead to better dispersion, which can expose more catalytic active sites, and obtain higher catalytic activity. Experiments indicate that Co3O4 HNCs are used as a catalyst to make H2O2 generate O2. At the same time, Co3O4 HNCs act as bridge to accelerate the electrons transfer from the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) to the dissolved oxygen and efficiently obtain blue oxidized TMB (oxTMB) at low concentration of H2O2. Steady-state kinetic analysis shows a lower Km and a higher Vmax value than other materials, indicating its excellent affinity and high catalytic efficiency. Based on the inhibitory effect of dopamine (DA) on TMB oxidation in the system, a sensitive, visual colorimetric biosensing method is developed. The calibration curve of DA has a good linear response at both high and low concentrations. Compared with other system, it has the unique advantage of very low detection limit, while retaining a wide detection range, and realizes the accurate detection of actual samples with different concentrations.

Enhancing photoluminescence of carbon quantum dots doped PVA films with randomly dispersed silica microspheres.

As a kind of excellent photoluminescent material, carbon quantum dots have been extensively studied in many fields, including biomedical applications and optoelectronic devices. They have been dispersed in polymer matrices to form luminescent films which can be used in LEDs, displays, sensors, etc. Owing to the total internal reflection at the flat polymer/air interfaces, a significant portion of the emitted light are trapped and dissipated. In this paper, we fabricate free standing flexible PVA films with photoluminescent carbon quantum dots embedded in them. We disperse silica microspheres at the film surfaces to couple out the total internal reflection. The effects of sphere densities and diameters on the enhancement of photoluminescence are experimentally investigated with a homemade microscope. The enhancement of fluorescence intensity is as high as 1.83 when the film is fully covered by spheres of 0.86 [Formula: see text]m diameter. It is worth noting that the light extraction originates from rather the scattering of individual spheres than the diffraction of ordered arrays. The mechanism of scattering is confirmed by numerical simulations. The simulated results show that the evanescent wave at the flat PVA/air interface can be effectively scattered out of the film.

Bidirectional Photochromism via Anchoring of Carbon Dots to TiO2 Porous Films.

Photochromic materials present photocontrollable properties, which is of great interest for potential applications including high-density storage and optical displays. Herein, we demonstrate a promising pathway toward smart photochromic nanocomposite exploration by anchoring of carbon dots (CDs) to titanium dioxide (TiO2) porous films. This study reveals that the color of the CDs/TiO2 film obtained by dropping anchoring becomes darker and that obtained by immersion anchoring becomes lighter, both under blue light irradiation. For the photobleaching material system, the spectral response is strongly dependent on wavelength and polarization of the exciting light, which provides new dimensions for optical information encryption and memory. This work lays the foundation for the materials platform in the integration of advanced information processing in the future.

Colorimetric and Raman spectroscopic array for detection of hydrogen peroxide and glucose based on etching the silver shell of Au@Ag core-shell nanoparticles.

Gold-silver core-shell nanoparticles (Au@Ag NPs) were prepared by two successive reductions in a seed-growth method. The Au@Ag NPs are used as both a colorimetric and Raman spectroscopic probe for ultrasensitive determination of H2O2 and glucose. It is found that H2O2 (as produced from glucose by the action of glucose oxidase) can directly oxidize and gradually corrode the silver shell of the Au@Ag NPs. This results in a drop in the surface plasmon resonance absorbance at 400 nm, and the color of the solution changes from brownish yellow to purple. Without adding any additional chromogenic agents, the color change can be visually observed and detected photometrically. Silver NPs also are an excellent surface-enhanced Raman scattering (SERS) substrate. Due to corrosion of the silver shell, the SERS intensity (measured at 1083 cm-1) gradually decreases with increasing glucose concentration. The detection limits are 300 nM of glucose for the colorimetric assays, and 20 nM for the SERS assay. Graphical abstractSchematic representation of the method for glucose determination. H2O2 can oxidize and gradually corrode the silver shell of the gold-silver core-shell nanoparticles. This results in a distinct color change of the solution from brownish yellow to purple, and a drop in SERS intensity. The effect is applied in colorimetric and Raman spectroscopic assays for glucose.

A nanocomposite prepared from silver nanoparticles and carbon dots with peroxidase mimicking activity for colorimetric and SERS-based determination of uric acid.

Silver-carbon dots (Ag-CDs) nanocomposites with excellent peroxidase-like and surface-enhanced Raman scattering (SERS) activities were fabricated by reducing silver ion with carbon dots. The formation of the core-shell structure was demonstrated by transmission electron microscopy. The Ag-CD nanocomposite catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to form oxidized TMB (oxTMB) that has a blue color with an absorption maximum at 652 nm. The catalytic activity originates from the fact that the electrons of CDs are transferred to H2O2 and decompose H2O2 into hydroxy radicals. The nanocomposites can be used for uric acid (UA) detection because UA can reduce oxTMB to form colorless TMB. The absorbance drops as the concentration of UA increases from 1 to 500 µM. The SERS signal of oxTMB can be detected (at 1605 cm-1) using the Ag-CD nanocomposites as SERS substrate. The intensity of the SERS signal decreases when the concentration of UA ranges from 0.01 to 500 µM. Graphical abstract Schematic representation of the fabrication of silver-carbon dots (Ag-CDs). The Ag-CDs catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to form blue-colored oxidized TMB (oxTMB). UA reduces oxTMB to form colorless TMB. This process is monitored by surface-enhanced Raman scattering (SERS) spectra for UA detection.

Carbon dots with molecular fluorescence and their application as a "turn-off" fluorescent probe for ferricyanide detection.

Highly fluorescent carbon dots (CDs) exhibiting molecular fluorescence were synthesized and successfully used for sensing ferricyanide based on fluorescence quenching. We conducted dialysis to purify the CDs and found that the dialysate is also fluorescent. From the mass spectra and quantum yield analyses of the dialysate, it is demonstrated that molecular fluorophores were also synthesized during the synthesis of CDs. By the comparison of fluorescence spectra between CDs and dialysate, it is established that the fluorescence emission of CDs partly originates from fluorophores that are attached to CDs' surface. The fluorescence quenching caused by ferricyanide is proved to be the overlap of absorption spectra between ferricyanide and CDs. The changes of the absorbance and fluorescence spectra are combined to enhance the detection sensitivity, and the limit of detection is calculated to be 1.7 µM. A good linear response of fluorescence-absorbance combined sensing toward ferricyanide is achieved in the range of 5-100 µM. This method is highly selective to ferricyanide among other common cations and anions, and it is also successfully applied in detecting ferricyanide in real water samples.

Apoferritin nanocages with Au nanoshell coating as drug carrier for multistimuli-responsive drug release.

Cancer is one of the major causes of mortality worldwide. Therefore, it is necessary to provide an effective method of tumor therapy. Herein, we designed a new type of composite particle, apoferritin (APO) encapsulated doxorubicin (DOX), and the surface of APO was modified with Au nanoshell. As a nanocarrier, APO can carry chemotherapy drug DOX (APODOX) and release drug under acidic and high temperature conditions to reduce side effects of anticancer drugs. After covering Au nanoshell (APODOX-Au), the photothermal effect can be produced because of the unique surface plasmon resonance properties of gold nanoshell. This nanoplatform also provides the multi-stimuli responsive drug release system, which can achieve drug release in different conditions and have great potential in biomedical applications. Our investigation has demonstrated that APODOX-Au has good stability, high dispersibility and biocompatibility in vitro. The strong near-infrared absorption and good photothermal effect make sure the quick response to environmental changes (pH, temperature) to achieve drug release. These findings indicate that these nanoparticles have a potential application value in cancer treatment.

First-principles study of electronic properties of Cu doped Ag2S.

Using first-principles calculations based on density functional theory, electronic properties of Ag2S and Cu doped Ag2S were investigated. The calculated results show that Ag2S crystal is semiconductor with a band gap of 0.92 eV which is consistent with previous PBE calculation. Three possible Cu doping configurations are investigated: Cu substitution of Ag_I, Cu substitution of Ag_II, and interstitial Cu. It is found that interstitial Cu doping reduces the band gap as the Cu concentration increases, while for Ag_I and Ag_II substitution doping the band gap is not sensitive to the impurity concentration. The band gap reduction can mainly be attributed to the downward shift of the bottom of conduction band upon Cu interstitial doping. The reduction of the band gap for Ag2S with interstitial Cu doping is consistent with experimental absorption and fluorescence spectra, where a significant red-shift after Cu doping in Ag2S crystal is observed.

Laser-induced formation of Au/Pt nanorods with peroxidase mimicking and SERS enhancement properties for application to the colorimetric determination of H2O2.

Platinum nanoparticles (PtNPs) were uniformly grown on the surface of gold nanorods (AuNRs) by a laser irradiation procedure. Transmission electron microscopy confirmed that the PtNPs are uniformly grown on the surface of the AuNRs. The formation of PtNPs on the AuNRs leads to a red-shift of the absorption maximum from 734 nm to 766 nm. In addition, the efficiency of surface enhanced Raman scattering (SERS) is increased, but the photothermal conversion efficiency is decreased compared to pure AuNRs. The result indicates that electron transfer occurs between gold and platinum. The peroxidase mimicking effect of PtNPs, AuNRs and Au/Pt NRs by catalyzing the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB; a quinone) in the presence of H2O2. The catalytic activity of Au/Pt NRs is higher than that of sole AuNRs or PtNPs by factors of 4.2 and 2.1, respectively. Thus, Au/Pt NRs have been used for the detection of peroxide and the limit of detection is 0.04 µM. This work provides an approach to integrate the peroxidase mimicking effect with SERS enhancement for potential application in detection. Graphical abstract A schematic diagram for the laser-induced growth of Au/Pt NRs and the colorimetric determination of hydrogen peroxide concentration with their peroxidase mimicking properties. The limit of detection is 0.04 µM based on the use of Au/Pt NRs as a catalyst.

Glycosylated liposomes loading carbon dots for targeted recognition to HepG2 cells.

It is important to obtain the targeted nanocarriers during cancer treatment. Herein, mannosylated liposomes encapsulating carbon dots (CDs) are provided for targeted recognition of liver cancer HepG2 cells, which is based on the specific interaction between D-mannose and glycoprotein on the surface of HepG2 cells. CDs were prepared by hydrothermal method. Then, they were encapsulated into liposomes by hydrophobic force. The encapsulation of CDs into liposomes increases their stability and fluorescence intensity. Furthermore, D-mannose can also be inserted into liposomes by the aldehyde amine reaction between aldehyde groups of mannose molecules and amino groups of liposomes. The obtained D-mannose-CDs-liposomes (Man-CDs-liposomes) exhibit selectively tracking and efficiently labelling for cancer cells. The work highlights the potential application of CDs for bioimaging and diagnostic.

SERS-active liposome@Ag/Au nanocomposite for NIR light-driven drug release.

It is important to control drug release and detect the distribution of drug molecules before and after release. In this work, liposome@AgAu nanocomposite is prepared for drug delivery, which not only can control drug release by near infrared laser irradiation but also can monitor drug molecules by surface enhanced Raman scattering (SERS) and fluorescence signal during the release process. The liposome@AgAu core/shell nanocomposite prepared by the galvanic replacement reaction (GRR) shows tunable localized surface plasmon resonance (LSPR) absorption peaks from visible to near-infrared region and good biocompatibility. Comparing to pure doxorubicin (DOX) molecules, liposome@AgAu nanocomposite loading DOX exhibit lower cytotoxicity by MTT assay. After loading into liposome@AgAu, the fluorescence signal of DOX disappear due to the fluorescence resonance energy transfer from DOX to metals shell. On the contrary, the SERS signal of DOX in liposome@AgAu is obviously increased. Furthermore, the liposome@AgAu nanocomposite shows photothermal conversion ability under resonance laser irradiation. Under 633nm laser irradiation, the liposome@AgAu nanocomposite loading DOX can release drug molecules for killing cancer cell. Meanwhile, the fluorescence signal from DOX appears after drug release from liposome@AgAu, but the SERS signal is not obvious. Therefore, this nanocomposite can provide a platform for photothermal controllable drug release and optical signal targeting for drug molecules.