Detection Of Acid Phosphatase Research Articles

Engineered nanozyme-cascade catalyzed reaction for rapid acid phosphatase detection

The utilization of artificial multienzyme-catalyzed cascade reactions have greatly benefited biosensors. This study presents a novel nanoreactor consisting of manganese ions-doped hollow carbon nanospheres (Mn@HCNs), which can rapidly transform molecular information into an easily comprehensible colorimetric signal. The Mn@HCNs nanoreactor was utilized to detect acid phosphatase (ACP) within a range of 0.5–10 mU/mL, achieving a limit of detection (LOD) as low as 0.0851 mU/mL. The superiority of our nanoreactor over traditional ACP detection methods stems from its exceptional substrate affinity and the multi-enzymatic behaviors of Mn@HCNs. Especially, the specific POD-like activity (SA) value of Mn@HCNs was superior to most reported Fe3O4 and other single-atom enzymes. Furthermore, this nanoreactor exhibited exceptional selectivity against protein and ion interference, and was furthered to detect ACP in clinical serum samples. The work may extend the development of artificial multienzyme-catalyzed cascade reactions for molecular biosensors and clinical application.

Synergistically enhanced water-resistive perovskite nanocrystals for cell nucleus imaging and acid phosphatase detection

Despite the impressive success of metal halide perovskite nanocrystals (NCs) in diverse fields, such as solar cells, light-emitting diodes, photodetectors, and so forth, their intrinsic sensitivity to water limits the extending applications in aqueous systems. Herein, enhanced water stability is achieved for NH2-PEG-COOH capped Mn2+-doped CsPbCl3/CsPb2Cl5 core/shell NCs through the synergistic effect of ion doping, core/shell construction and polymer encapsulation. The NH2-PEG-COOH encapsulation is validated crucial for the formation of CsPbCl3/CsPb2Cl5 core/shell structure, since it retains contact for CsPbCl3 NCs with trace water, and guarantees a slow water-etching process, triggering the CsPbCl3 to CsPb2Cl5 transformation. Thanks to the high formation energy induced by Mn2+ doping, CsPbCl3/CsPb2Cl5 hetero core/shell construction and NH2-PEG-COOH protective barrier, the obtained NCs exhibit unattenuated photoluminescence quantum yield after dipped in water for 15 days. Based on the robust water stability, the NH2-PEG-COOH capped Mn2+-doped CsPbCl3/CsPb2Cl5 NCs work well in cell nucleus imaging and acid phosphatase detection. This work not only produces a novel perovskite fluorescence probe in aqueous systems but also provides a general and effective combination strategy to enhance the water stability of perovskite materials.

Phosphorus Modulated Peroxidase-Like Activity of Carbon Dots for Colorimetric Detection of Acid Phosphatase.

The precise regulation of nanoenzyme activity is of great significance for application to biosensing analysis. Herein, the peroxidase-like activity of carbon dots was effectively modulated by doping phosphorus, which was successfully employed for sensitive, selective detection of acid phosphatase (ACP). Phosphorus-doped carbon dots (P-CDs) with excellent peroxidase-like activity were synthesized by a one-pot hydrothermal method, and the catalytic activity could be easily modulated by controlling the additional amount of precursor phytic acid. P-CDs could effectively catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue TMB oxidation products in the presence of hydrogen peroxide. While ACP was able to catalyze the hydrolysis of L-ascorbyl-2-phosphate trisodium salt (AAP) to produce ascorbic acid (AA), which inhibited the peroxidase-like activity of P-CDs, by combining P-CDs nanoenzymes and ACP-catalyzed hydrolysis the colorimetric method was established for ACP detection. The absorbance variation showed a good linear relationship with ACP concentration in the range of 0.4-4.0 mU/mL with a limit of detection at 0.12 mU/mL. In addition, the method was successfully applied to detect ACP in human serum samples with recoveries in the range of 98.7-101.6%. The work provides an effective strategy for regulating nanoenzymes activity and a low-cost detection technique for ACP.

Colorimetric Detection of Acid Phosphatase and Malathion Using NiCo2O4 Nanosheets as Peroxidase-Mimicking Activity

Colorimetric Detection of Acid Phosphatase and Malathion Using NiCo2O4 Nanosheets as Peroxidase-Mimicking Activity

Single-step colorimetric detection of acid phosphatase in human urine using an oxidase-mimic platinum nanozyme

A nanozyme sensor for rapid detection of urinary acid phosphatase with high sensitivity and a broad dynamic range that is relevant to human pathophysiology is proposed.

Fluorometric and colorimetric quantitative analysis platform for acid phosphatase by cerium ions-directed AIE and oxidase-like activity.

A facile and sensitive fluorescent and colorimetric dual-readout assay for detection of acid phosphatase (ACP) was developed via Ce(III) ions-directed aggregation-induced emission (AIE) of glutathione-protected gold nanoclusters (GSH-AuNCs) and oxidase-mimicking activity of Ce(IV) ions. Free Ce(IV) ions exhibited a strong oxidase-mimetic activity, catalytically oxidizing colorless 3,3',5,5'-tetramethylbenzidine (TMB) into its blue product oxTMB in the presence of dissolved O2, thus triggering a remarkable color reaction detectedvisually. ACP can hydrolyze L-ascorbic acid-2-phosphate (AAP) with the production of ascorbic acid (AA). The AA is able to reduce Ce(IV) ions to Ce(III) ions, thus quenching the oxidase-mimetic activity of Ce(IV) ions. Meanwhile, Ce(III) ions induce AIE of GSH-AuNCs, resulting in the enhancement of thefluorescence signal of GSH-AuNCs. Both the fluorescent and colorimetric dual-mode analysis platforms exhibit a sensitive response to ACP, providing detection limits as low as 0.101 U/L and 0.200 U/L, respectively. Besides, this fabricated dual-mode detection platform holds the potential for analysis of ACP in human serum samples and screening inhibitors for ACP. With good performance and practicability, this study shows promising application in the convenient and reliable determination of ACP activity.

Adjustable luminescence copper nanoclusters nanoswitch based on competitive coordination of samarium ions for cascade detection of adenosine triphosphate and acid phosphatase activity.

Benefit from the strong coordination property, lanthanide metal ions have been used as competitive reagents to modulate the fluorescence changes of the system. However, lanthanide metal ions as inducers for aggregation-induced emission enhancement in nanosystems is rare. Herein, we report a "turn on-off-on" fluorescent switch for cascade detection of acid phosphatase (ACP) and adenosine triphosphate (ATP) based on the competitive coordination of samarium ions (Sm3+). Novel copper nanoclusters (CuNCs) with long wavelength emission (614nm) stabilized by glutathione (GSH) and glycylglycine (Gly-Gly) have been confirmed to have AIE property. With the continuous aggregation of GSH/Gly-Gly CuNCs under the induction of Sm3+, the fluorescence of the system increased to achieve the "turn-on" process. The coordinated behaviour between Sm3+ and GSH/Gly-Gly CuNCs is discussed. Due to the strong metal coordination ability of ATP, the Sm3+ coordinated with the GSH/Gly-Gly CuNCs is competed out, resulting in the fluorescence "turn-off" process of the system. As the substrate of enzymatic hydrolysis of ACP, with the continuous hydrolysis of ATP by ACP, Sm3+ coordinates with GSH/Gly-Gly CuNCs again, which leads to the AIE effect and realize the fluorescence "turn-on" process of the system. This strategy results inATP linear range of 0.508 ~ 120.0μM with a detection limit of 0.508μM (S/N = 3) and ACP linear range of 0.011 ~ 30.0 U·L-1 with a detection limit of 0.011 U·L-1 (S/N = 3). Application tobiologic samples wassuccessful.

Indirect detection of acid phosphatase at the macroscopic electrified liquid-liquid interface

Acid phosphatase (AcidP) is a biomarker of prostate cancer (PC) when found in blood and urine at elevated levels. Moreover, AcidP could also be used as a target biomarker in presumptive test for the presence of semen in case of sexual assault. Therefore, this preliminary work proposes an alternative approach for the electrochemical (cyclic voltammetry) detection of AcidP having specific activity ≥0.4 unit·mg−1 over electrified liquid-liquid interface (eLLI). Proposed idea is simple and based on the reaction catalyzed by AcidP, this is hydrolysis of phosphocholine ester (PCE) resulting in the production of choline that generate electrochemical signal upon potential difference controlled transfer across the eLLI. Mechanisms, interfacial behavior, physicochemical parameters pertaining to choline, PCE and AcidP have been studied using cyclic voltammetry. Observed optimal parameters were employed for the indirect detection of the AcidP in the presence of PCE. We have found that when the mixture of AcidP and PCE were incubated for 24 h at 37 ˚C in 10 mM Britton-Robinson-Buffer (pH 4.8) the clear signals attributed to choline transfer started appearing within the available potential window. Even with very low specific activity of AcidP (only 0.4 unit·mg−1), eLLI based enzyme biosensor demonstrated a linear detection range from 0.4 to 2.0 mg·mL−1 with experimental detection limit of 0.4 mg·mL−1. Moreover, sensitivity of the proposed biosensor was found 5.15 µA·L·g−1. Results obtained in this study can be considered as the proof of concept with high potential for the detection of AcidP in real clinical and forensic samples.

Phosphorescence, fluorescence, and colorimetric triple-mode sensor for the detection of acid phosphatase and corresponding inhibitor

Acid phosphatase (ACP) as a clinical diagnostic biomarker for several pathophysiological diseases has aroused widespread interest. Compared to commonly developed single-mode ACP detection technology, the multi-mode detection method with self-validation can provide more reliable results. Herein, we proposed a triple-mode phosphorescence, fluorescence, and colorimetric method for ACP detection in combination with CDs@SiO2. HAuCl4 with oxidase-like activity can catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to the blue oxide TMB (TMBox), offering absorption signals and quenching the phosphorescence and fluorescence of CDs@SiO2 based on the internal filtration effect (IFE). ACP can hydrolyze ascorbic acid 2-phosphate (AAP) to yield ascorbic acid (AA), thereby reducing TMBox to TMB, triggering solution fading and restoring phosphorescence and fluorescence signals. When the ACP inhibitor malathion is present, the reduction of TMBox is hindered, which successively led to the suppression of CDs@SiO2 phosphorescence and fluorescence signal recovery. According to these principles, triple-mode ACP (LOD = 0.0026 mU mL−1) and malathion detections (LOD = 0.039 μg mL−1) with favorable accuracy and sensitivity are realized. With simplicity, robustness, and versatility, the triple-mode sensor can be extended to the detection of the AAP hydrolase family and the screening of corresponding inhibitors.

Malathion detection based on polydopamine enhanced oxidase-mimetic activity of palladium nanocubes

Nowadays, fabricating simple and efficient pesticide detection methods become a research focus due to the great threat pesticide residues posed to human health and environment. Herein, we constructed a high-efficiency and sensitive colorimetric detection platform for malathion detection based on polydopamine-dressed Pd nanocubes (PDA-Pd/NCs). The Pd/NCs coated with PDA exhibited excellent oxidase-like activity, which was attributed to the substrates accumulation and accelerated electron transfer induced by PDA. What's more, we successfully achieved sensitive detection of acid phosphatase (ACP) using 3,3′,5,5′-tetramethylbenzidine (TMB) as the chromogenic substrate, relying on the satisfactory oxidase activity from PDA-Pd/NCs. However, the addition of malathion could inhibit the activity of ACP and limit the production of medium AA. Therefore, we constructed a colorimetric assay for malathion based on PDA-Pd/NCs + TMB + ACP system. The wide linear range (0–8 μM) and low detection limit (0.023 μM) indicate excellent analytical performance, which is superior to most malathion analysis methods previously reported. This work not only provides a new idea for dopamine coated nano-enzyme to improve its catalytic activity, but also creates a new tactics for the detection of pesticides such as malathion.

Large-scale synthesis of high loading Co single-atom catalyst with efficient oxidase-like activity for the colorimetric detection of acid phosphatase

Single-atom catalysts (SACs) have shown broad application prospects in different area due to their maximum atomic utilization and excellent catalytic properties. However, how to realize large-scale synthesis of high loading SACs is still a problem for various application requirements. Herein, we report a novel strategy to synthesize Co single-atom catalyst (Co-SAC) by controllable releasing of Co atoms at high temperature, which can be effective to avoid the formation of Co nanoparticles. Particularly, the synthesized Co-SAC with Co content of 7.04 wt% contained exclusive single Co atoms coordinated Co-N4 active sites, demonstrated by inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray absorption spectroscopy (XAS). The obtained Co-SAC exhibited excellent intrinsic oxidase-like activity by catalyzing the dissolved oxygen to superoxide radicals. Based on the antioxidant of ascorbic acid (AA) and the enzymatic property of acid phosphatase (ACP), a colorimetric assay for AA and ACP was established by utilizing the oxidase-like activity of Co-SAC. The results indicated that the limit of detection (LOD) of AA and ACP was 1.31 μM and 0.08 U/L, respectively. Considering the large-scale synthetic method and its excellent catalytic property, this kind of Co-SAC would have a good prospect in biosensor fields.

Fluorescence dual “turn-on” detection of acid phosphatase via fluorescence resonance energy transfer and dual quenching strategy to improve sensitivity

A fluorescent dual “turn-on” method is utilized to detect acid phosphatase (ACP) via dual quenching and fluorescence resonance energy transfer (FRET) strategy to improve sensitivity for the first time. Bovine serum albumin protected gold nanoclusters (BSA-AuNCs) are utilized as fluorescence probe and peroxidase-mimicking catalyst. BSA-AuNCs oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to TMB (oxTMB) with the absorbance peak at 652 nm. Fluorescence spectrum of BSA-AuNCs with emission peak at 635 nm is largely overlapped with absorption spectrum of oxTMB, which brings FRET from BSA-AuNCs to oxTMB and fluorescence is quenched. When Ce3+ is added, BSA-AuNCs catalyze the oxidation of Ce3+ to Ce4+ by H2O2. Ce4+ has oxidizing properties, which can oxidize TMB into oxTMB and enhance FRET. It achieves the fluorescence is quenched further more. This dual fluorescence quenching effect brings a low background for ACP detection. ACP catalyzes ascorbic acid 2-phosphate (AA2P) hydrolysis into phosphate ion (PO43−) and ascorbic acid (AA). Owing to high coordination between Ce3+ and PO43−, TMB oxidation is prevented and fluorescent is turned-on. AA reduces oxTMB into TMB, which makes FRET be prevented and fluorescence is also increased. Therefore it is utilized in ACP detection from 0.01 to 2 U/L with high selectivity and accuracy.

Biomimetic cascade nanoreactor with triple-enzyme mimetic activities for colorimetric detection of acid phosphatase

Delighted by the high catalytic efficiency and superior selectivity of multiple enzyme-driven biological catalytic cascades, biomimetic cascade nanoreactors have drawn much attention recently. Here, a new type of biomimetic cascade nanoreactor – Co nanoparticles embedded N-enriched carbon nanocubes (Co,N-CNC) which derived from ZIF-67 nanocubes was designed and utilized for acid phosphatase (ACP) detection. The distinctive composition and cubic structure endowed Co,N-CNC with significantly enhanced triple-enzyme mimetic activities, including oxidase (OXD)-, peroxidase (POD)-, and catalase (CAT)-like activities. Employing the OXD- and POD-like activities of Co,N-CNC nanoreactor, a cascade amplification strategy was proposed for the first time for ACP colorimetric detection without the assistance of destructive H2O2. Based on the high catalytic activity of Co,N-CNC and the cascade amplification strategy, a good linear relationship was obtained from 0.01 to 10.0 mU/mL, with a lower detection limit of 6.1 μU/mL. Significantly, the Co,N-CNC could detect ACP in human serum samples with high accuracy. Therefore, the Co,N-CNC nanoreactor with triple-enzyme mimetic activities displayed broad prospects for biosensing, medical diagnostics and biotechnological research.

Construction of a Carbon Dots/Cobalt Oxyhydroxide Nanoflakes Biosensing Platform for Detection of Acid Phosphatase.

Because abnormal acid phosphatase (ACP) can disrupt the normal physiological processes, determination of ACP level is extremely important for early diagnosis, treatment, and prognostic evaluation of diseases. Herein, a fluorescence platform for monitoring ACP level was established based on the assembly of red-emitting carbon dots (RCDs) on cobalt oxyhydroxide (CoOOH) nanoflakes. RCDs displayed excellent water solubility, pH stability, salt resistance, and photobleaching resistance. Interestingly, the fluorescence of the RCDs assembled on the surface of the CoOOH nanoflakes could be quenched due to the energy transfer caused by the nanoflakes. However, the ascorbic acid (AA) produced by the hydrolysis of ascorbic acid-2-phosphate trisodium salt (AAP) catalyzed by ACP could quickly and effectively reduce CoOOH nanoflakes, leading to the fluorescence recovery of the RCDs. Therefore, an "off-on" biosensor platform for rapid, sensitive, and selective detection of ACP was constructed with a limit of detection of 0.25 mU/L. With the assistance of the biosensor, the level of ACP in human serum samples was evaluated, and the spike recovery values ranged from 94.0% to 104.5%.

A dual-signal fluorescent probe for detection of acid phosphatase.

Acid phosphatase has become a significant indicator of prognostic and medical diagnosis, and its dysfunction may lead to a series of diseases. A novel dual-signal fluorescence method for acid phosphatase detection based on europium polymer (europium-pyridine dicarboxylicacid-adenine) and pyridoxal phosphate (PLP) was proposed. PLP coordinated with europium polymer via Eu3+ and P-O bonds, and the fluorescence of europium polymer was quenched due to the photoinduced electron transfer (PET) effect between aldehyde and europium polymer. Upon addition of acid phosphatase, the PLP was transformed to phosphate (Pi) and pyridoxal (PL). The PL was released from the surface of europium polymer, and the blue emission was enhanced due to the formation of internal hemiacetal, while the fluorescence of europium polymer recovered. The blue (PL) and red emission (Eu3+) were positively correlated with acid phosphatase activity; thus the sensitive assay of acid phosphatase was effectively achieved. The two signals were applied to determine the acid phosphatase with limits of detection (LOD) of 0.04mU/mL and 0.38mU/mL, and the linear ranges were 0.13-5.00mU/mL and 1.25-20.00mU/mL, respectively. The probe can be used to trace the acid phosphatase in biological systems and holds promise for use in clinical diagnosis and early prevention.

Smartphone based highly sensitive visualized detection of acid phosphatase enzyme activity.

With the rapid development of point-of-care (POC) technologies, development of sensitive method featured with fast analysis and affordable devices has become an emerging requirement for practical applications. In this study, we introduced a smartphone-based RGB analysis system for the sensitive detection of acid phosphatase (ACP) enzyme activity. In the presence of ACP, l-ascorbic acid 2-phosphate (AAP) can be converted into ascorbic acid (AA), which can reduce Ag+ to Ag0 and format the Au@Ag core-shell nanostructure. This morphology change of the Au@Ag core-shell would trigger a significant color variation (pink to yellow). A good linear relationship between the RGB model parameter and the concentration of ACP could be obtained with a detection limit of 0.1 U L-1. Moreover, this sensing strategy is suitable for the detection of ACP in practical serum samples. Thus, this simple but powerful protocol has great potential application for on-site detection of ACP in future complex biological samples.

Biomimetic Cascade Nanoreactor with Triple-Enzyme Mimetic Activities for Colorimetric Detection of Acid Phosphatase

Biomimetic Cascade Nanoreactor with Triple-Enzyme Mimetic Activities for Colorimetric Detection of Acid Phosphatase

A feasible self-assembled near-infrared fluorescence sensor for acid phosphatase detection and cell imaging.

The single signal amplification strategy is significant for detecting various disease biomarkers but is restricted by its limited accuracy. The multi-signal and multi-mode methods have overcome this deficiency. Acid phosphatase (ACP) is an important intracellular enzyme but one-step cell imaging material-based probes are scarce for ACP. Herein, we designed a one-step self-assembled polymer probe using neutral red (NR), modified-(pyridoxal-5'-phosphate (PLP)) and Eu3+. The polymer exhibited non-emission and excellent stability. Upon the catalytic hydrolysis reaction of ACP, the polymer exhibited two strong fluorescence signals at 373 nm and 613 nm and an appreciable decline of absorbance at 395 nm. The probe has excellent selectivity and higher sensitivity with a limit of detection as low as 0.02 mU mL-1. It possesses favorable biocompatibility and has been successfully used to detect and image intracellular ACP in several living cells.

Visual detection of acid phosphatase based on hollow mesoporous manganese dioxide nanospheres

Acid phosphatase is widely used as a clinical indicator because of its close correlation with a variety of diseases. Herein, a label-free and colorimetric sensing method for detecting the activity of acid phosphatase was constructed based on hollow mesoporous manganese dioxide nanospheres. The nanospheres exhibit superior oxidase-like property and can oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to yellow TMB2+. Ascorbic acid from acid phosphatase-catalyzed hydrolysis of L-ascorbic acid-2-phosphate will inhibit the oxidization reaction, igniting vivid color variation. On the basis of this obvious multicolor change, the visual detection of acid phosphatase was achieved. Compared with the single-color change, the multicolor colorimetric method is more conducive for naked-eye discrimination. The absorbance difference at 450 nm exhibits a linear relationship with the concentration of acid phosphatase ranging from 1.0 to 25 U L−1, with a detection limit as low as 0.45 U L−1. Acid phosphatase in human serum samples was successfully determined. Moreover, the inhibition efficiency of NaF for acid phosphatase activity was investigated, proving the proposed colorimetric method will be a potential platform for screening acid phosphatase inhibitors and discovering new drugs.

In Situ Enzymatic Generation of Gold Nanoparticles for Nanozymatic Label-free Detection of Acid Phosphatase

Pronounced changes of acid phosphatase (ACP) in the human body may occur because of several diseases. Unusual ACP expressions might be diagnostically useful as serological and histological biomarke...