Plasmon Resonance Energy Transfer Research Articles

Tunable Plasmonic Random Laser Based on Emitters Coupled to Plasmonic Resonant Nanocavities of Silver Nanorod Arrays (Advanced Optical Materials 10/2022)

A tunable plasmonic random laser based on emitters coupled to plasmonic resonant nanocavities is demonstrated by Junxi Zhang, Fei Wang, Zhijia Hu and co-workers (see article number 2200426). The random laser with a low threshold, excited over threshold in comparison with the wide and weak emission below threshold, results from plasmon resonance energy transfer, enhanced localized electric fields, and multiple light scattering from the disorder–order hybrid silver nanorod arrays. The lasing wavelength can be tuned by harmonic modes of the nanocavities.

Single particle plasmonic and electrochemical dual mode detection of amantadine

Herein, a facile and sensitive dual mode sensing strategy for amantadine (AMD) level evaluation by coupling the plasmonic Au nanorod (NR) and supramolecular SH-cyclodextrin (CD) through strong Au-S bond is proposed. Methylene blue (MB) molecules can be inserted into the cavity of CD molecules through the hydrophobic interaction, which would cause the plasmon resonance energy transfer (PRET) process as well as electrochemical signal response due to the spectrum overlap between Au NR and MB molecules and the electrochemical conversion activity of MB molecules. Subsequently, AMD would induce the replacement of MB molecules because of the stronger interaction with CD, resulting the recovery of scattering intensity of Au NR and decrease of the electrooxidation current of MB. On one hand, the increase of Au NR scattering intensity is linearly proportional to AMD with the concentration from 0.4 to 3.0 μM, and reaches a limit of detection (LOD) of 0.28 μM. On the other hand, electrochemical measurement method enlarged the detection range of AMD. The variation of electrochemical oxidation peak current of MB is linearly proportional to the logarithm value of AMD concentration from 2.5 to 375.0 μM, with LOD of 1.9 μM. Subsequently, the proposed dual mode response sensing strategy was successfully employed for the detection of AMD in human serum samples with great selectivity and sensitivity, with a recovery percentage ranged from 92.6 to 112.0%. Overall, this Au NR@SH-CD-MB nanoparticle based single particle plasmonic and electrochemical dual mode sensing method provides great potential in the field of clinical drug detection or metabolic process investigation in the future.

Tunable Plasmonic Random Laser Based on Emitters Coupled to Plasmonic Resonant Nanocavities of Silver Nanorod Arrays

AbstractRandom lasers are generated by multiple light scattering in disordered optically gain medium, which are fundamentally different from conventional lasers. Control of emission properties, especially emission wavelength for random lasers is still challenging due to absence of optical cavity. Although plasmonic random lasers exhibit well‐controlled properties, most of studies on plasmonic random lasers to date are still focused on scattering amplification by disorder metal nanoparticles. Here, a tunable random laser based on emitters of Nile red/poly‐methyl methacrylate (PMMA) coupled to plasmonic resonant nanocavities of silver nanorod arrays is presented. The plasmonic random laser has very strong and narrow emission peaks and a very low lasing threshold of 22.8 µJ, resulting from plasmon resonance energy transfer (PRET), the enhanced absorption, scattering, and excitation rates of Nile red/PMMA due to strong localized electric fields in the nanocavities, and enhanced multiple light scattering from the disorder–order hybrid silver nanorod arrays. Furthermore, the lasing wavelength can be tuned in a wide range from 623 to 654 nm by different order harmonic modes of the plasmonic resonant nanocavities. This work not only provides a new strategy to design tunable random lasers, but also opens up their potential applications in medicine and sensing.

Recent Advances in Plasmonic Photocatalysis Based on TiO2 and Noble Metal Nanoparticles for Energy Conversion, Environmental Remediation, and Organic Synthesis

AbstractPlasmonic photocatalysis has emerged as a prominent and growing field. It enables the efficient use of sunlight as an abundant and renewable energy source to drive a myriad of chemical reactions. For instance, plasmonic photocatalysis in materials comprising TiO2 and plasmonic nanoparticles (NPs) enables effective charge carrier separation and the tuning of optical response to longer wavelength regions (visible and near infrared). In fact, TiO2‐based materials and plasmonic effects are at the forefront of heterogeneous photocatalysis, having applications in energy conversion, production of liquid fuels, wastewater treatment, nitrogen fixation, and organic synthesis. This review aims to comprehensively summarize the fundamentals and to provide the guidelines for future work in the field of TiO2‐based plasmonic photocatalysis comprising the above‐mentioned applications. The concepts and state‐of‐the‐art description of important parameters including the formation of Schottky junctions, hot electron generation and transfer, near field electromagnetic enhancement, plasmon resonance energy transfer, scattering, and photothermal heating effects have been covered in this review. Synthetic approaches and the effect of various physicochemical parameters in plasmon‐mediated TiO2‐based materials on performances are discussed. It is envisioned that this review may inspire and provide insights into the rational development of the next generation of TiO2‐based plasmonic photocatalysts with target performances and enhanced selectivities.

Ultrasensitive Capsaicin Sensor Based on Endogenous Single‐Molecule Fluorophore Enhancement and Quenching Interface on Gold Nanoislands

Ultrasensitive capsaicin sensor based on endogenous single‐molecule fluorophore enhancement and quenching interface on gold nanoislands (GNIs) was developed by correlative fluorescence fluctuation optical spectroscopy. Endogenous fluorescence of capsaicinoids was enhanced by plasmon resonance energy transfer in the proximity of GNIs. The enhanced fluorescence signals exhibited large fluctuation from the average intensity reflecting the characteristic to‐and‐fro Brownian motion of fluorophores to the proximity of GNIs. The fluctuation of fluorophores showed enhancement, quenching, and equilibrium lifetimes depending on fluorophore‐GNI distance. The correlation diffusion of fluorophore signal decreased with increasing concentration of capsaicinoids. In the cross‐correlative quantification of capsaicinoids using the GNI array chip, the method showed excellent detection limits of 290 zM for capsaicin and 467 zM for dihydrocapsaicin. This method consisting of fluorophore fluctuation analysis and correlation diffusion‐based quantification has potential application to the study of label‐free single‐molecule interactions.

Nanohole array structured GaN-based white LEDs with improved modulation bandwidth via plasmon resonance and non-radiative energy transfer

Commercial white LEDs (WLEDs) are generally limited in modulation bandwidth due to a slow Stokes process, long lifetime of phosphors, and the quantum-confined Stark effect. Here we report what we believe is a novel plasmonic WLED by infiltrating a nanohole LED (H-LED) with quantum dots (QDs) and Ag nanoparticles (NPs) together (M-LED). This decreased distance between quantum wells and QDs would open an extra non-radiative energy transfer channel and thus enhance Stokes transfer efficiency. The presence of Ag NPs enhances the spontaneous emission rate significantly. Compared to an H-LED filled with QDs (QD-LED), the optimized M-LED demonstrates a maximum color rendering index of 91.2, a 43% increase in optical power at 60 mA, and a lowered correlated color temperature. Simultaneously, the M-LED exhibits a data rate of 2.21 Gb/s at low current density of 96 A / cm 2 (60 mA), which is 77% higher than that of a QD-LED. This is mainly due to the higher optical power and modulation bandwidth of the M-LED under the influence of plasmon, resulting in a higher data rate and higher signal-to-noise ratio under the forward error correction. We believe the approach reported in this work should contribute to a WLED light source with increased modulation bandwidth for a higher speed visible light communication application.

Bioelectronic Measurement of Target Engagement to a Membrane-Bound Transporter.

The ability to detect and characterize drug binding to a target protein is of high priority in drug discovery research. However, there are inherent challenges when the target of interest is an integral membrane protein (IMP). Assuming successful purification of the IMP, traditional approaches for measuring binding such as surface plasmon resonance (SPR) and fluorescence resonance energy transfer (FRET) have been proven valuable. However, the mass dependence of SPR signals may preclude the detection of binding events when the ligand has a significantly smaller mass than the target protein. In FRET-based experiments, protein labeling through modification may inadvertently alter protein dynamics. Graphene Bio-Electronic Sensing Technology (GBEST) aims to overcome these challenges. Label-free characterization takes place in a microfluidic chamber wherein a fluid lipid membrane is reconstituted directly above the GBEST sensor surface. By leveraging the high conductivity, sensitivity, and electrical properties of monolayer graphene, minute changes in electrostatic charges arising from the binding and unbinding of a ligand to a native IMP target can be detected in real time and in a mass-independent manner. Using crude membrane fractions prepared from cells overexpressing monocarboxylate transporter 1 (MCT1), we demonstrate the ability to (1) form a fluid lipid bilayer enriched with MCT1 directly on top of the GBEST sensor and (2) obtain kinetic binding data for an anti-MCT1 antibody. Further development of this novel technology will enable characterization of target engagement by both low- and high-molecular-weight drug candidates to native IMP targets in a physiologically relevant membrane environment.

Establishment of Novel Protein Interaction Assays between Sin3 and REST Using Surface Plasmon Resonance and Time-Resolved Fluorescence Energy Transfer.

Repressor element-1 (RE-1) or neural restrictive silencer element (NRSE) bound with a zinc finger transcription repressor, RE-1 silencing transcription factor (REST, also known as neural restrictive silencer factor, NRSF) has been identified as a fundamental repressor element in many genes, including neuronal genes. Genes regulated by REST/NRSF regulate multifaceted neuronal phenotypes, and their defects in the machinery cause neuropathies, disorders of neuron activity), autism and so on. In REST repressions, the N-terminal repressor domain recruits Sin3B via its paired amphipathic helix 1 (PAH1) domain, which plays an important role as a scaffold for histone deacetylase 1 and 2. This machinery has a critical role in maintaining neuronal robustness. In this study, in order to establish protein–protein interaction assays mimicking a binding surface between Sin3B and REST, we selected important amino acids from structural information of the PAH1/REST complex and then tried to reconstitute it using recombinant short peptides derived from PAH1/REST. Initially, we validated whether biotinylated REST interacts with glutathione S-transferase (GST)-tagged PAH1 and whether another PAH1 peptide (PAH1-FLAG) competitively binds with biotinylated REST using surface plasmon resonance (SPR). We observed a direct interaction and competitive binding of two PAH1 peptides. Secondly, in order to establish a high-throughput and high-dynamic-range assay, we utilized an easily performed novel time-resolved fluorescence energy transfer (TR-FRET) assay, and closely monitored this interaction. Finally, we succeeded in establishing a novel high-quality TR-FRET assay and a novel interaction assay based on SPR.

Facile synthesis of biomass silica-silver colloidal nanoparticles and its application as highly sensitive fluorescent biosensor

Colloidal inorganic nanoparticles have a significant impact for biosensing due to its precise biomolecular interaction. Herein, we report on the efficiency of silica-silver colloidal nanoparticles towards optical biosensor application. Silica colloids was prepared by the sol-gel method using biomass of rice husk as a precursor and then composited with silver colloids. The size of silica and silver (SiO2-Ag) colloidal nanoparticles was found to be 80 nm and 75 nm, respectively. The SiO2-Ag colloidal nanoparticles have the unique fluorescence at 325 nm with an excitation of 260 nm, which is significant for the excitation of most biomolecules, organelle stains and fluorescent labelling. The biosensing properties were validated against biomolecules such as glucose, uric acid, paracetamol, ascorbic acid and dopamine through plasmon resonance energy transfer (PRET) process by fluorescence spectroscopic technique. The glucose molecules responded with good sensing efficacy and the detection limit was found to be 0.49 µM. The proof of efficient glucose sensing of the SiO2-Ag colloidal nanoparticles also validated on human urine and serum and it gives the maximum recovery of 99.3 % and 98.2 %, respectively. These results support the efficacy of SiO2-Ag colloidal nanoparticles for optical biosensing applications in future.

C-Mpl-del, an Alternative Splicing Isoform of c-Mpl, Promotes Malignancy and Chemoresistance of AMKL by Regulating AKT/DDIT3 Survival Signaling

Background: Acute megakaryocytic leukemia (AMKL) is a clinically heterogeneous subtype of acute myeloid leukemia (AML) characterized by unrestricted megakaryoblast proliferation, myelofibrosis, and poor prognosis. Aberrant c-Mpl signaling has been implicated in a myriad of myeloid proliferative disorders, some of which can lead to AMKL, however the role of c-Mpl in AMKL progression remains largely unexplored. Methods: Quantitative real-time PCR and Western blot were carried out to identify the expression of c-Mpl variants. The binding affinities of c-Mpl to TPO and c-Mpl dimerization were investigated by surface plasmon resonance, microscale thermophoresis, and fluorescence resonance energy transfer. RNA-Seq, Co-IP, and Western blot were performed to examine the functional mechanism of c-Mpl variants in AMKL development and chemotherapy response. Finding: We identified increased expression of a c-Mpl isoform (c-Mpl-del) in the bone marrow of AMKL patients and AMKL cell lines. c-Mpl-del overexpression was correlated with enhanced AMKL cell proliferation and chemotherapeutic resistance, and decreased survival in xenografted mice. Interestingly, c-Mpl-del exhibits decreased receptor internalization resulting in increased surface stability and allowed for sustained TPO signaling. These led to the preferential phosphorylated c-Mpl-del C-terminus Y607 and biased activation of PI3K/AKT pathway, which culminated in downregulation of DDIT3-related apoptotic responses conducive to AMKL survival and proliferation. Interpretation: This study elucidates a novel role of c-Mpl in AMKL progression and drug resistance, which not only improves our understanding of c-Mpl-dependent leukemia development, but also has important implications in prognosis and treatment of AMKL. Funding: A full list of funding can be found in the Acknowledgments section. Declaration of Interest: All authors declare that they have no conflict of interest. Ethical Approval: All clinical samples were obtained with informed consent from Sun Yat-sen University Cancer Center and approved by the Hospital’s Ethical Review Committees. The animal studies were authorized by the Animal Ethic Review Committees of the Sun Yat-sen University.

Nanosilver supported on inert nano-diamond as a direct plasmonic photocatalyst for degradation of methyl blue

Direct photocatalysis with plasmonic nanostructures represents a new and promising direction in pollutant disposal. In current practice, inert metal oxides are usually used as supports to load plasmonic nanoparticles. However, due to the lack of stabilizing functional groups on the surface of these metal oxides, the stability and dispersibility of the obtained nanostructures are poor. Herein, a nano-diamond (ND) material with easily functionalized surface was used as an inert support to load silver nanoparticles to prepare plasmonic nanostructures with direct photocatalytic ability. The plasmonic nanostructure can be easily prepared by modifying the surface of ND with pyridine groups and then reducing the silver precursor in-situ. Thanks to pyridine group's dual functions of complexing Ag nanocrystals and dispersing ND, the obtained plasmonic nanostructure not only has uniformly distributed Ag nanocrystals on ND surface, but also shows excellent multi-solvent dispersibility. we demonstrate that this novel plasmonic nanostructure can directly decolorization of methyl blue (MB) under visible light irradiation with a standard rate constant as high as 28.4 s−1 g−1. In addition, the catalyst can be easily recovered and recycled for at least five times while maintaining high catalytic activity. The mechanism study shows that the localized surface plasmon resonance energy transfer of Ag nanoparticles is the direct driving force of MB degradation. The inert ND support can not only ensure the physical stability of Ag nanoparticles, but also avoid the attenuation of plasmonic resonance energy to matrix, which plays an indispensable synergistic role in promoting the rapid degradation of MB.

"Loading-type" Plasmonic Nanoparticles for Detection of Peroxynitrite in Living Cells.

To date, plasmon resonance energy transfer (PRET)-based analytical approaches still inevitably suffer from limitations, such as lack of appropriate acceptor-donor pairs and the extra requirements of active groups of acceptors, which place great obstacles in extending the application of such methods, especially in the area of living cell studies. Herein, we design and fabricate a kind of "loading-type" plasmonic nanomaterials constituting gold nanoparticles as donors of PRET coated with mesoporous silicon, in which organic small molecules (CHCN) as acceptors of PRET were loaded (Au@MSN-CHCN). This "loading-type" strategy could conveniently integrate acceptor-donor pairs into one nanoparticle, so as to achieve the goal of sensitive detection of biomolecules in a complex physiological microenvironment. Based on the change of PRET efficiency of Au@MSN-CHCN induced by the specific reaction between CHCN and peroxynitrite (ONOO-), ONOO-, which plays an irreplaceable role in a series of physiological and pathological processes, is sensitively and selectively detected. Furthermore, in situ imaging of exogenous and endogenous ONOO- in living cells was achieved even at a single nanoparticle level. This work provides a general approach to construct PRET probes for visualizing various biomolecules in living cells.

Distance-Dependence Study of Plasmon Resonance Energy Transfer with DNA Spacers.

Plasmon resonance energy transfer (PRET) in hybrid plasmonic-molecular systems has a broad range of applications from catalysis to analytical/biochemical/biophysical imaging and sensing. Herein, we experimentally and theoretically probed the influence of the distance (d) between the plasmonic nanoparticle and the conjugated molecules on the PRET efficiency (ηPRET) using two PRET systems, which involved tetramethylrhodamine (TAMRA) or Cy3 molecules as acceptors and single spherical gold nanoparticles (AuNPs) as donors. The double-stranded DNA (dsDNA) sequences precisely adjusted within 12.0 nm were utilized as a donor-acceptor spacer. Then, the ηPRET of the two systems under varied d-values was available from the reduction of the scattering intensity of AuNPs. Both experimental and quasi-static approximation data show that ηPRET displays a d-value-dependent decay function. This study would provide new insights into optimal PRET-based chemical/biochemical sensors.

Gated Resonance Energy Transfer (gRET) Controlled by Programmed Death Protein Ligand 1.

The resonance energy transfer (RET) between an excited fluorescent probe molecule and a plasmonic nanoparticle (AuNP) has been investigated to evaluate the effect of protein molecules on the RET efficiency. We have found that the energy transfer to a functionalized AuNP can be modulated by a sub-monolayer film of programmed death-ligand 1 (PD-L1) protein. The interactions of PD-L1 with AuNP@Cit involve incorporation of the protein in AuNP shell and formation of a submonolayer adsorption film with voids enabling gated surface plasmon resonance energy transfer (SPRET). A model of the gated-RET system based on the protein size, estimated using Fisher–Polikarpov–Craievich density approximation, has been developed and can be utilized for other proteins, with minimum data requirement, as well. The value of the equilibrium constant KL determined for the Langmuir isotherm is high: KL = 1.27 × 108 M−1, enabling highly sensitive control of the gated-RET by PD-L1. Thus, with the gated-RET technique, one can determine PD-L1 within the dynamic range, extending from 1.2 to 50 nM. Moreover, we have found that the Gibbs free energy for PD-L1 binding to AuNP@Cit is −46.26 kJ/mol (−11.05 kcal/mol), indicating a strong adsorption with supramolecular interactions. The proposed gated-RET system, with the fluorescence intensity of the fluorophore probe molecule modulated by plasmonic quenching with AuNP and shielding of energy transfer by the adsorbed PD-L1 can be further developed for determination of PD-L1 in pharmaceutical formulations for immune checkpoint control in cancer therapy.

Selective Ultrasensitive Optical Fiber Nanosensors Based on Plasmon Resonance Energy Transfer.

The facet of optical fibers coated with nanostructures enables the development of ultraminiature and sensitive (bio)chemical sensors. The sensors reported until now lack specificity, and the fabrication methods offer poor reproducibility. Here, we demonstrate that by transforming the facet of conventional multimode optical fibers onto plasmon resonance energy transfer antenna surfaces, the specificity issues may be overcome. To do so, a low-cost chemical approach was developed to immobilize gold nanoparticles on the optical fiber facet in a reproducible and controlled manner. Our nanosensors are highly selective as plasmon resonance energy transfer is a nanospectroscopic effect that only occurs when the resonance wavelength of the nanoparticles matches that of the target parameter. As an example, we demonstrate the selective detection of picomolar concentrations of copper ions in water. Our sensor is 1000 times more sensitive than the state-of-the-art technologies. An additional advantage of our nanosensors is their simple interrogation; it comprises of a low-power light-emitting diode, a multimode optical fiber coupler, and a miniature spectrometer. We believe that the plasmon resonance energy transfer-based fiber-optic platform reported here may pave the way for the development of a new generation of ultraminiature, portable, and hypersensitive and selective (bio)chemical sensors.

Intriguing Plasmonic and Fluorescence Duality in Copper Nanoparticles

Dendrimeric copper nanoparticles (CuNPs) were prepared by the reduction of [Cu2(CH3CO2)4] with ascorbic acid at 75 °C in the presence of ranelate ions. The metallic nanoparticles exhibited a strong plasmonic band centered at 581 nm, and their average size distribution was typically in the range of 20–30 nm. By adding polyvinylpyrrolidone to the reaction mixture, the growth of the initial copper nanoparticles was hindered. Their sizes were stabilized around 1.8 nm, leading to spherical agglomerates of about 50 nm. Upon green light excitation, the agglomerates exhibited yellow-orange fluorescence emission, keeping the surface plasmon resonance band at 581 nm. This dual behavior suggested the occurrence of collective plasmonic resonance and efficient energy transfer within the agglomerated nanoparticles, in order to account for the observed fluorescence in the system.

Electronic structures associated with enhanced photocatalytic activity in nanogap-engineered g-C3N4/Ag@SiO2 hybrid nanostructures

Graphitic carbon nitride (g-C3N4) has attracted considerable attention with regard to its use in photocatalytic solar hydrogen production by the splitting of water. High charge carrier recombination critically limits the photocatalytic activity of g-C3N4. Plasmonic metal nanoparticles that can generate localized surface plasmon resonance (LSPR) have been suggested to enhance the harvesting of visible light and to improve water splitting efficiency. However, direct contact between metal nanoparticles and g-C3N4 reduces the hydrogen generation efficiency owing to energy loss by Förster resonance energy transfer (FRET), which competes with plasmon resonance energy transfer (PRET). Decorating g-C3N4 with Ag@SiO2 core-shell plasmonic nanoparticles increases its photocatalytic ability. Tuning the size of the SiO2 nanogap can optimize the photocatalytic performance of g-C3N4/Ag@SiO2, which involves a trade-off between PRET and FRET. X-ray absorption spectroscopy (XAS) is utilized to investigate the electronic structure of g-C3N4 and its modulation with Ag@SiO2. In situ XAS reveals the dynamics of the charge carriers under solar illumination. Analytic results suggest charge redistribution, shifting of the conduction band, modification of the unoccupied states, and consequent improvement in photocatalytic activity by solar illumination. This work sheds light on the effect of LSPR on this photocatalyst with reference to its electronic structure.

Improved CdS photocatalytic H2 evolution using Au-Ag nanoparticles with tunable plasmon-enhanced resonance energy transfer.

Plasmon-mediated photocatalytic systems often suffer from weak absorption spectra overlap which limits energy transfer between plasmon metals and semiconductors. Herein, Au-Agx@CdS90 nanoparticles (NPs) with adjustable spectral overlap were prepared. Au-Ag hollow nanoparticles (HNPs) with tunable plasmon absorption peaks were used as the template and were coated with CdS to achieve stepwise spectral overlap for enhanced energy transfer. As the spectral overlap increased between Au-Ag HNPs and CdS, the H2 evolution rate increased and then decreased. Under visible-light irradiation, Au-Ag487@CdS90 nanoparticles (NPs) delivered an H2 evolution rate of 18.73 mmol h-1 g-1, which was 2.2 times higher than pure CdS. The plasmon resonance energy transfer from Au-Ag HNPs to the CdS semiconductor increased the generation of charge carriers in the semiconductor and enhanced the photocatalytic performance. By regulating the position of the plasmon absorption peaks of the noble metal nanoparticles, changing the spectral overlap between metal and semiconductor to enhance the PRET effect is beneficial to the design of new plasmon photocatalysts.

Plasmon-stimulated biophotovoltaic cells based on thylakoid–AuNR conjugates

Enhanced photosynthetic current and improved bio-photovoltaic cells are demonstrated using plasmon resonance energy transfer of plasmon nanoparticle-conjugated thylakoid membranes.

Enzyme Activity Triggered Blocking of Plasmon Resonance Energy Transfer for Highly Selective Detection of Acid Phosphatase.

Plasmon resonance energy transfer (PRET), as a new form of energy transfer first discovered in 2007, has been widely applied for the biomolecular recognition, detection of ions, cellular physiological status monitoring, and energy conversion. It occurs between noble metal nanoparticles (donor) and conjugated molecules or nanoparticles (acceptor). In this study, we used urchin-like gold nanoplasmonics (UGPs) and oxTMB as a new donor-acceptor pair to establish a novel PRET coupling system, avoiding trivial modification. PRET from UGPs to conjugated redox-active oxTMB leads to resonant quenching in the localized surface plasmon resonance (LSPR) spectra. However, when the acid phosphatase (ACP) was introduced, the hydrolyzate ascorbic acid (AA) converted from 2-phospho-l-ascorbic acid trisodium salt (AAP) could be capable of reducing oxTMB into TMB, thereby preventing the occurrence of PRET. The recovery of the scattering spectral intensity of UGPs was linearly related to the concentration of ACP in the range of 0.1 to 5.0 U/L, and the ACP with a detection limit of 0.076 U/L could be measured. In addition, this method also showed good selectivity attributed to the substrate specificity of enzyme.