Coated Au Nanoparticles Research Articles

Au/Doc/Quer@PDA/A10-3.2 Nanoparticles for targeted treatment of docetaxel-resistant prostate cancer

Docetaxel (Doc), as a first-line chemotherapy drug for prostate cancer (PC), often loses its therapeutic efficacy due to acquired resistance and lack of targeting specificity. Therefore, there is a need to develop a novel drug that can overcome Doc resistance and enhance its targeting ability to inhibit PC progression. In this study, we prepared Au/Doc/Quer@PDA/A10-3.2 nanoparticles (NPs) composite drug by encapsulating Doc and quercetin (Quer) within polydopamine (PDA)-coated Au NPs and further modifying them with RNA oligonucleotide aptamer A10-3.2. A10-3.2 was used for specific targeting of prostate-specific membrane antigen (PSMA)-positive PC cells (LNCaP). Quer was employed to reverse the resistance of Doc-resistant cell line (LNCaP/R) to Doc. Physical characterization using ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful preparation of Au/Doc/Quer@PDA/A10-3.2 NPs. Fluorescence imaging and flow cytometry experiments demonstrated the targeting ability of Au/Doc/Quer@PDA/A10-3.2 NPs towards PSMA-positive LNCaP/R cells. Cell proliferation, apoptosis, invasion, and migration experiments revealed that Quer reversed the resistance of LNCaP/R cells to Doc. Immunoblotting experiments further confirmed the mechanism behind sensitization of chemotherapy by Quer. Finally, we evaluated the therapeutic efficacy of Au/Doc/Quer@PDA/A10-3.2 NPs in a mouse model of PC. In conclusion, this study synthesized and validated a novel nano-composite drug (Au/Doc/Quer@PDA/A10-3.2 NPs) for combating Doc-resistant PC, which could potentially be applied in clinical treatment of PC.

Label-free SERS method with size-matched selectivity for analytes of varying sizes

Label-free Surface-enhanced Raman spectroscopy (SERS) methods have great potential for detecting analytes of various sizes and dimensions with high sensitivity and selectivity. To mitigate the impact of interfering substances, SERS-active substrates with size-matched selectivity were designed by coating Au nanoparticles (Au NPs) on ZrO2 multilayer nanofibers (Au NPs/fZrO2) and referencing with Au NPs embedded on ZrO2 nanobowl (Au NPs/pZrO2). The detection efficiency study covered four small pesticide molecules, two live SARS-CoV-2 virus variants (Alpha and Delta), and three interfering substances. The results demonstrate that the fibrous structure of Au NPs/fZrO2 could effectively wet the sample and detect larger target molecules, such as live SARS-CoV-2 virus, thus improving efficiency by reducing unwanted molecules in the SERS signal. This substrate also showed high discrimination between Alpha and Delta variants. Au NPs/fZrO2 demonstrated similar trace detection capabilities to Au NPs/pZrO2 for pesticide molecules and virus variants; however, it particularly exhibited stronger peak intensities and more unique SERS peaks assigned to the variants. Thus, differences in substrate morphology affect the generation of hotspots and the distance between analyte and hotspots. These findings hold promise for the development of SERS-based label-free analytical method for trace detection of a variety of virus particles.

Amalgamation of DNAzymes and Nanozymes in a Coronazyme.

Artificial enzymes such as nanozymes and DNAzymes are economical and stable alternatives to natural enzymes. By coating Au nanoparticles (AuNPs) with a DNA corona (AuNP@DNA), we amalgamated nanozymes and DNAzymes into a new artificial enzyme with catalytic efficiency 5 times higher than AuNP nanozymes, 10 times higher than other nanozymes, and significantly greater than most of the DNAzymes on the same oxidation reaction. The AuNP@DNA demonstrates excellent specificity as its reactivity on a reduction reaction does not change with respect to pristine AuNP. Single-molecule fluorescence and force spectroscopies and density functional theory (DFT) simulations indicate a long-range oxidation reaction initiated by radical production on the AuNP surface, followed by radical transport to the DNA corona, where the binding and turnover of substrates take place. The AuNP@DNA is named coronazyme because of its natural enzyme mimicking capability through the well-orchestrated structures and synergetic functions. By incorporating different nanocores and corona materials beyond DNAs, we anticipate that the coronazymes represent generic enzyme mimics to carry out versatile reactions in harsh environments.

MnO2 coated Au nanoparticles advance SERS detection of cellular glutathione

Glutathione, referred to as GSH, abnormal physiologic level of GSH is an indication to some neurodegenerative diseases and cancers. A measurement of cellular GSH calls for rapid, sensitive, and selective methods. In this work, we rationally design and prepare Au@MnO2 core-shell composite nanoparticles combining with tetramethylbenzidine (TMB) molecules to determine intracellular GSH by Surface enhanced Raman scattering (SERS) technique. MnO2 plays multifunctional roles in the method, including the participation in catalyzing TMB to molecules form dimer charge-transfer complex (CTC) which own a great SERS signal reporter. With the addition of GSH, the MnO2 will be dissolving detaching CTC molecules from the surface of Au@MnO2 and resulting in a signal-off off SERS response and indirect and sensitive detection of GSH could be realized. The limit of detection of GSH by SERS method is as low as 0.1 μmol/L and a good linear relationship of GSH is found in the range from 0.5 to 30 μmol/L. Au@MnO2-SERS assay is successfully applied to detect cellular GSH, which is validated by using Enzyme-linked-immunoassay-based Kit. The Au@MnO2-SERS protocol has promising potential for clinical application.

Swelling triggered release of cisplatin from gelatin coated gold nanoparticles

In the present study gelatin coated-gold nanoparticles were synthesized and release study of the drug cisplatin was carried out in a swelling controlled manner. In-situ method was adopted, for preparing gelatin coated-Au nanoparticles. Prepared nanoparticles were characterized by FTIR, SEM, TEM, XRD, EDAX and In-vitro cytotoxicity techniques. The data of drug release processes were analyzed kinetically using Fickian power law, zero order, first order and Korsmeyer–Peppas models. Fourier transform infrared (FTIR) spectroscopy confirms the interactions between drug and gelatin coated-Au nanoparticles. SEM images showed that the drug loaded nanoparticles have rough and porous surfaces. The particle size, as measured by TEM technique, revealed that the size of cisplatin loaded gelatin coated-Au nanoparticles lies up to about 100 nm. The maximum drug loading was 74.3%. The release of cisplatin could be best described by Korsmeyer–Peppas model as evident from non-Fickian transport mechanisms having the value R2 = 0.997, respectively.

Surface second harmonic generation spectra of titania coated Au NPs

Surface second harmonic generation (s-SHG) spectra of supported Au nanoparticles (NPs) with titania coating are presented. Although the optical properties of these particles are in agreement with the predictions from Mie theory and previously reported literature, s-SHG spectra over a relatively broad spectral range, allows for the extraction of additional information regarding the morphology of the sample. These geometrical findings need to be considered while interpreting the observed spectra of supported NPs. In the case of atomic layer deposition of TiO2 onto Au NPs, it is found that for the titania layers thinner than 5 nm in nominal terms, Au NPs are not fully covered, as titania preferably accumulates at the space between the particles and at particles’ edges and corners. Full encapsulation of the Au NPs is achieved for titania films with a nominal thickness of more than 5 nm. Furthermore, s-SHG spectra can also be used to extract information on the size distribution of the NPs.

Synthesis and Characterization of Graphene Oxide Coated Au Nano Particles and The Study of its Application on Electro Catalytic Activity of Nitric Oxide

Synthesis and Characterization of Graphene Oxide Coated Au Nano Particles and The Study of its Application on Electro Catalytic Activity of Nitric Oxide

Synthesis, Characterization and Investigation of Water Uptake Capacity of Gelatin Coated Gold Nanoparticles

The present research work focuses on the designing of gelatin coated-Au nanoparticles and evaluating their water imbibitions capacity at different experimental conditions. Gelatin nanoparticles were synthesized by single water in oil (W/O) emulsion cross-linking technique and gold nanoparticles by Turkvitch method. For preparing these nanocarriers, ex-situ as well as in-situ methods were adopted and the prepared gelatin coated-Au nanoparticles were characterized by FTIR, SEM, TEM, XRD and in-vitro cytotoxicity techniques. The effect of various experimental conditions, such as amount of gelatin content, pH, temperature, and simulated biological fluids were investigated on the swelling behavior of nanoparticles. The as prepared gelatin coated-Au nanoparticles could be applied as nanocarriers for delivery of anticancer drugs.

Chemical modification of M13 bacteriophage as nanozyme container for dramatically enhanced sensitivity of colorimetric immunosensor

Herein, a sulfydryl modification of M13 bacteriophage was introduced as bio-functional component including biological recognition, and nanozyme container for enhancing sensitivity of colorimetric immunsensor, where the seven peptide sequence fused on the p3 protein of M13 was used to mimic deoxynivalenol (DON) antigen for recognizing the anti-DON monoclonal antibody, while the sulfydryl groups modified on capsid proteins were used to load numerous Ag coated Au nanoparticles (AuNPs@Ag) for improving the peroxidase-like activity of AuNPs@Ag. Owing its great loading capacity, the M13 bacteriophage assembled AuNPs@Ag nanocomposites (M13DON@AuNPs@Ag) showed approximately 48- and 105-fold enhanced catalytic efficacy to hydrogen peroxide and tramethylbenzidine than those of natural horse radish peroxidase (HRP). Using the M13DON@AuNP@Ag as signal amplifier, the proposed immunosensor exhibits a very high sensitivity for DON detection with the 50 % competitive inhibition concentration (IC50) and detection limit (LOD) of 2.03 ng/mL and 13.67 pg/mL, respectively. These values are about 26- and 947-fold lower than those of conventional HRP based ELISA method (IC50 and LOD values =52.43 ng/mL and 12.95 ng/mL, respectively). In addition, the proposed method also showed good specificity and accepted accuracy for DON detection in real corn samples. Moreover, the reliability of this novel strategy was further confirmed through compared with the high performance liquid chromatography method (HPLC). All in all, the M13 bacteriophage exhibits a promising potential as nanozyme container for enhancing the sensitivity of immunosensor, and this novel signal amplification system can be easily extended for highly sensitive detection of other analytes by altering specific mimic peptide sequence.

Simultaneous Detection of Inflammatory Biomarkers by SERS Nanotag-Based Lateral Flow Assay with Portable Cloud Raman Spectrometer.

Inflammatory biomarkers are closely related to infectious diseases. However, traditional clinical tests of laboratory inspection are unable to achieve rapid and accurate detection of these biomarkers on-site due to shortcomings such as complex experimental operation, expensive equipment, and long test time. Herein, we proposed a lateral flow assay (LFA) strip based on surface-enhanced Raman scattering (SERS) nanotags (SERS-LFA strips) for the simultaneous and quantitative detection of dual infection biomarkers, serum amyloid A (SAA) and C-reactive protein (CRP), respectively. In practice, mesoporous silica (mSiO2)-coated Au nanoparticles (Au NPs) were used as the SERS substrate. Mercaptobenzoic acid (MBA) was embedded in the internal gap between Au NPs and the mSiO2 shell to prepare AuMBA@mSiO2 NPs, onto which SAA and CRP antibodies were modified to prepare two AuMBA@mSiO2 SERS nanotags. The Raman intensities of the test and control lines were simultaneously identified for the qualitative detection of SAA and CRP, with limits of detection (LODs) as low as 0.1 and 0.05 ng/mL for SAA and CRP, respectively. Finally, aiming at point-of-care testing (POCT) applications, we used a smartphone-based portable Raman spectrometer to quantitatively analyze the SERS-LFA strips. The Raman signal could still be accurately detected when the concentration of SAA and CRP was 10 ng/mL, which is lower than the LOD required in clinical practice for most diseases. Therefore, taking into account its simple operation and short analysis time, by using a portable Raman spectrometer which can be equipped with a 5G cloud-based healthcare management system, the current strategy based on SERS-LFA provides the potential for the quick and on-site diagnosis of infectious diseases such as sepsis, which is of great significance for medical guidance on the treatment of widely spread infection-related diseases in remote areas that lack well-developed medical resources.

Mapping Adsorbates with Shell-Isolated Nanoparticle Enhanced Raman Spectroscopy to Understand Rapid Superconformal Filling of Cu Trenches

Additive adsorbates are widely used as surfactants to guide morphological and microstructural evolution during electrochemical deposition of thin films. Even though this strategy has been employed for several decades understanding of the mechanisms at play on the interface remain limited. Modern spectroelectrochemical methods, from surface-enhanced Raman spectroscopy (SERS) to surface-enhanced infrared spectroscopy (SEIRAS) and non-linear optical methods like sum frequency generation (SFG) can provide significant insight into the composition, structure, and dynamics of the surfactant adsorbates through their vibrational signatures. on nominally static surfaces. Each strategy is limited to specimen geometry; SERS is closely linked to the use of rough, plasmonically-active surfaces while SEIRAS measurements are constrained to thin, IR-transparent, metallic films. In the last decade, a significant advance was the introduction of nanoparticle reporters, based largely on silica coated Au nanoparticles, that enable Raman spectroscopy studies on well-defined, single-crystal surfaces whereby the nanoparticle serves to channel the plasmonic energy to the nanoparticle-substrate interface. The silica or alternative coating materials are designed to be inert with respect to the chemistry of the adsorbate species under study while remaining thin enough to allow effective focusing of the optical energy. This approach has been adopted by several researchers interested in understanding molecular adsorption on well-defined, single-crystal surfaces, the electrical double layer, and numerous aspects of reactivity related to catalysis, batteries, electrodeposition, etc. The present work demonstrates the use of Au@SiO2 (core-shell) nanoparticles, also known as SHINERS (Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy), to enable in situ vibrational spectroscopic measurements during electroplating of comparatively smooth, rapidly advancing, surfaces. In particular, the ability of the reporters to float on an advancing surface while responding to area change is used to reveal important, area-driven changes in adsorbate coverage. This study also opens a new avenue for exploring the intersection of analytical surface chemistry and composite electroplating. Figure 1

Pulmonary fate and consequences of transferrin-functionalized gold nanoparticles.

Surface functionalization of nanoparticles (NPs) may alter their biological interactions such as uptake by alveolar macrophages (AMs). Pulmonary delivery of gold NPs (Au NPs) has theranostic potential due to their optoelectronic properties, minimal alveoli to blood translocation, and possibility of specific cell targeting. Here, we examined whether coating Au NPs with transferrin alters their protein corona, uptake by macrophages, and pulmonary translocation.Methods: Rats were intratracheally instilled with transferrin-coated Au NPs (Tf-Au NPs) or polyethylene glycol-coated Au NPs (PEG-Au NPs). AMs were collected and processed for quantitation of Au cell uptake using ICP-MS and electron microscopy. Au retention in the lungs and other organs was also determined. The uptake of fluorescently labeled Tf-Au NPs and PEG-Au NPs by monocyte-derived human macrophages was also evaluated in vitro.Results: We showed that Tf-Au NPs were endocytosed by AMs and were retained in the lungs to a greater extent than PEG-Au NPs. Both Au NPs acquired similar protein coronas after incubation in rat broncho-alveolar lavage fluid (BALf). The translocation of Au from both NPs to other organs was less than 0.5% of the instilled dose. Transferrin coating enhanced the uptake of Au NPs by primary monocyte-derived human macrophages.Conclusions: We report that coating of NP surface with transferrin can target them to rat AMs and human monocyte-derived macrophages. NP functionalization with transferrin may enhance NP-based therapeutic strategies for lung diseases.

In vitro investigation of swelling triggered release of 5-fluorouracil from gelatin coated gold nanoparticles

In the present study gelatin coated-gold nanoparticles were synthesized and release study of the drug “5-fluorouracil” (5-FU) was carried out in a controlled manner. Gelatin nanoparticles were prepared by single water in oil (W/O) emulsion crosslinking technique and gold (Au) nanoparticles by Turkvitch method. For preparing gelatin coated-Au nanoparticles, in situ method was adopted. The release kinetics of entrapped drug was investigated as a function of various experimental factors such as chemical composition of prepared nanoparticles, pH, temperature and simulated biological fluids as the release media. The 5-FU drug loaded nanoparticles were characterized by FTIR, SEM, TEM, XRD and in vitro cytotoxicity techniques. The drug release process was analyzed kinetically using Fickian power law, zero order, first order and Korsmeyer–Peppas models, respectively, and a correlation was established between the quantity of the released drug and swelling of the nanoparticles.

Biofunctional Polymer Coated Au Nanoparticles Prepared via RAFT-Assisted Encapsulating Emulsion Polymerization and Click Chemistry.

The use of reversible addition-fragmentation chain transfer (RAFT)-assisted encapsulating emulsion polymerization (REEP) has been explored to prepare diverse types of colloidal stable core–shell nanostructures. A major field of application of such nanoparticles is in emergent nanomedicines, which require effective biofunctionalization strategies, in which their response to bioanalytes needs to be firstly assessed. Herein, functional core–shell nanostructures were prepared via REEP and click chemistry. Thus, following the REEP strategy, colloidal gold nanoparticles (Au NPs, d = 15 nm) were coated with a poly(ethylene glycol) methyl ether acrylate (PEGA) macroRAFT agent containing an azide (N3) group to afford N3–macroRAFT@Au NPs. Then, chain extension was carried out from the NPs surface via REEP, at 44 °C under monomer-starved conditions, to yield N3–copolymer@Au NPs–core–shell type structures. Biotin was anchored to N3–copolymer@Au NPs via click chemistry using an alkynated biotin to yield biofunctionalized Au nanostructures. The response of the ensuing biotin–copolymer@Au NPs to avidin was followed by visible spectroscopy, and the copolymer–biotin–avidin interaction was further studied using the Langmuir–Blodgett technique. This research demonstrates that REEP is a promising strategy to prepare robust functional core–shell plasmonic nanostructures for bioapplications. Although the presence of azide moieties requires the use of low polymerization temperature, the overall strategy allows the preparation of tailor-made plasmonic nanostructures for applications of biosensors based on responsive polymer shells, such as pH, temperature, and photoluminescence quenching. Moreover, the interaction of biotin with avidin proved to be time dependent.

A fluorescent and colorimetric probe of carbyne nanocrystals coated Au nanoparticles for selective and sensitive detection of ferrous ions

Dual-functional nanosensors for fluorescent and colorimetric detection of metal ions are generally shown in organic materials or complex organic-inorganic hybrid structures, and there are much few reports about dual-functional sensors made of pure and simple inorganic nanomaterials. Here, we report a fluorescent and colorimetric probe of the hybrid gold-carbyne nanocrystals structure for selective and sensitive detection of ferrous ions. We fabricate fluorescent carbyne nanocrystals (inorganic nanocrystals) capped with gold nanoparticles (CNCs@AuNPs) via a convenient one-step laser ablation in liquids. We demonstrate that, with involvement of ferrous ions, CNCs@AuNPs show fluorescence-quenching and color-producing properties, which make them be a double-channel platform for chemical and biomedical detection. With remarkably high selectivity towards ferrous ions over other metals, the fluorescent and colorimetric methods of the fabricated probe exhibit a detection limit of 14 μM and 1.2 μM, respectively. We also establish that the electron transferring plays an important role in facilitating these novel effects. These findings expand the applications of inorganic nanomaterials in chemical and biomedical sensing.

Fe(III) Mixed IP6@Au NPs with Enhanced SERS Activity for Detection of 4-ATP

Surface Enhanced Raman Scattering (SERS) has been widely applied in many research fields such as biological detection and chemical analysis. However, for the common Au nanoparticles, it’s too hard to guarante the three aspects: the great enhanced effect, the controllable aggregation and the uniformity of nanoparticles, the environmental friendliness and biocompatibility of nanoparticles. In this paper, phytate acid (IP6)-coated Au nanoparticles (IP6@Au NPs) are more stable and have a higher enhancement factor than Au nanoparticles. In order to achieve the uniformity of the spherical IP6-coated@Au nanoparticles (IP6@Au NPs), IP6 was used as a soft template. In the presence of IP6, IP6@Ag nanoparticles were first synthesized by reducing AgNO3 with trisodium citrate, then IP6@Au NPs were obtained by reducing HAuCl4 with Ag nanoparticles. The IP6@Au NPs exhibit excellent Raman signal enhancement by using p-aminothiophenol (4-ATP) as the probe molecules. The effects of Fe3+ on the performance of IP6@Au NPs SERS substrates were also studied. The results show that SERS has the best enhancement effect when adding proper amount of Fe3+ (0.56 PPM), and the limit of detection was 10−7 M 4-ATP.

Observation of high efficient photothermal conversion of sub-10 nm Au nanoparticles coated on upconversion nanoparticles

Gold nanoparticles have been confirmed to be very suited for applications in cancer photothermal therapy. However, nanoscale photothermal conversion mechanisms of Au nanoparticles are still not completely unveiled. Here, we employ upconversion nanoparticles (UCNPs) as nanoscale light sources, of which green emission centered at 540 nm can be efficiently absorbed by Au nanoparticles with an average diameter of 4 nm. Gold nanoparitcles (~4 nm) are coated on upconversion nanoparticles (UCNPs) with an average diameter of 90 nm, while the gap among these coated Au nanoparticles is smaller than 20 nm which is obviously shorter than the half wavelength (270 nm) of green emission of UCNP core nanoparticles. As a result, green emission of UCNPs could not penetrate the coating of Au nanoparticles without being absorbed. Based on UCNPs@Au nanosystems, high efficient photothermal conversion of Au nanoparticles can be directly observed, while a photothermal conversion efficiency of 41.2% is determined. Importantly, fluorescent resonance energy transfer (FRET) mechanisms from UCNPs to Au nanoparticles is confirmed to be the predominant route for this nanoscale photothermal system (UCNPs@Au), instead of direct photon absorption.

Sensitive Colorimetric Detection of Prostate Specific Antigen Using a Peroxidase-Mimicking Anti-PSA Antibody Coated Au Nanoparticle

The use of colorimetric bioassays for protein detection is one of the most promising diagnostic approaches, but their relatively poor detection limits have been a critical issue. In this study, we developed an efficient colorimetric bioassay based on antibody-coated peroxidase-mimicking Au nanoparticles (Au NPs) for the detection of prostate-specific antigen (PSA), which is one of the most widely used protein biomarkers for the diagnosis of prostate and breast cancers. Anti-PSA antibody adsorption on the Au NP surface result in 65% of the peroxidasemimicking properties of Au NPs was suppressed to maximize sensitivity of the assay. Anti-PSA antibody adsorption on the Au NP was optimized at 150 µg/mL anti-PSA4 antibody for 1 h incubation, and their surface was blocked with 2% BSA. The experimental conditions of the immunoassay detection were also investigated. A highest assay value was obtained at 10 µg/mL anti-PSA1 capture antibody using 3% BSA for surface blocking and at 2.5 pM anti- PSA4-Ab coated Au NPs for 1 h incubation with PSA antigen. As a result, PSA was detected at a wide range of 0.25 to 2,500 ng/mL with a detection limit of 0.23 ng/mL. The anti-PSA-Ab coated Au NP- based assay was simple, easy to operate, and sensitive. The proposed peroxidase-mimicking anti-PSA Ab-coated Au NP-based assay could be further developed to detect other protein biomarkers.

Dendrimer‐Based Gold Nanostructures for SERS Detection of Pesticides in Water

Dendrimers are polymers with well‐defined architectures and tunable chemistry, which make them useful in a number of applications. Herein, the chemistry of poly(amido)amine (PAMAM) dendrimers with different functional groups was explored to produce a variety of plasmonic systems based on Au colloidal nanoparticles. The resulting systems present long‐term colloidal stability and were investigated as sensitive platforms for surface‐enhanced Raman scattering (SERS). The application of these SERS platforms for the detection of water trace pollutants, was explored through the analysis of selected pesticides. Noteworthy, dendrimer coated Au nanoparticles with tunable properties such as size, shape and surface chemistry, were obtained by varying the dendrimer chemical properties. The surface chemistry of PAMAM capped Au colloids was explored in order to produce target selective SERS substrates for pesticide detection, that allowed to reach detection limits down to 10 nm.

Highly selective detection of l-Phenylalanine by molecularly imprinted polymers coated Au nanoparticles via surface-enhanced Raman scattering

Molecularly imprinted film coated gold nanoprticles (MIP-AuNPs) were employed as surface-enhanced Raman scattering (SERS) substrate for sensitive and selective recognition and quantification of l-Phenylalanine (L-Phe). The MIP was in-situ formed on the AuNPs by sol-gel technique using L-Phe as the template molecule, tetraethyl orthosilicate as the crosslinker and phenyltrimethoxysilane as the functional monomer. The efficient removal of template was achieved by ultrasonic treatment. The as-prepared MIP-AuNPs sensor showed a good linear relationship with the concentration of L-Phe in the range of 1.0 × 10−8–1.0 × 10−4 mol L−1 with a limit of detection as low as 1.0 nmol L−1. The sensor also showed an excellent selectivity as L-Phe can be determined in the presence of other amino acid analogues, D-Phe and bovine serum. The stability of the MIP-AuNPs was manifested by the low deviation (RSD = 3.7%) for 40 days subsequent measurements.