Poly(N-2-hydroxypropylmethacrylamide)-capped gold nanoparticles as nanozymes with peroxidase-mimicking performance for the colorimetric monitoring of serum homocysteine.

Recently, nanozymes based on polymer-stabilized gold nanoparticles (AuNPs) have attracted more and more attention on account of their polymer-ligands' multiple functionalization sites. However, the contribution of polymer hydrogen bonding to the catalytic activity of AuNPs has received little attention. This study designed and fabricated poly(N-2-hydroxypropylmethacrylamide)-capped AuNPs (PHPAM@AuNPs) using a hydroxyl-rich polymer as the ligand. The PHPAM@AuNPs exhibited good peroxidase-mimicking activity capable of efficiently oxidizing 3,3'5,5'-tetramethylbenzidine (TMB) with H2O2. The effect of PHPAM hydrogen bonding on the catalytic activity of PHPAM@AuNPs was investigated. Under peroxidase-mimicking catalysis, homocysteine introduced a notable reduction in oxidation, allowing the creation of a colorimetric method for homocysteine detection with high selectivity and sensitivity. The ultraviolet-visible absorption intensity of oxidized TMB showed a strong linear relationship with homocysteine concentration in the range of 3.0-20.0 µM (R2 = 0.998), with a limit of detection of 0.4 µM. The proposed colorimetric protocol was used to monitor homocysteine in rat serum following intraperitoneal injection. This work provides a new way to refine AuNP-based nanozymes by relying on polymer-ligand hydrogen bonding. It has strong application potential in the analysis of endogenous molecules in real samples.

Redox-Responsive Polymer Nanoreactors Based on Methionine Sulfoxide for Monitoring Cell Adhesion.

Expanding the category of redox-responsive monomers suitable for enzymolysis efficiency regulation and application to living biosystems is a prerequisite to complementing the fabrication of stimuli-responsive polymer nanoreactors. However, the development of redox-responsive monomers is severely limited by chemical oxidation and low biocompatibility. This work presents a protocol for overcoming this problem by the self-assembly of redox-responsive polymer nanoreactors containing segments of water-soluble methionine sulfoxide residues and poly(styrene-co-maleic anhydride-l-methionine), and by immobilizing α-l-fucosidase into the nanoreactors. These nanoreactors demonstrate highly selective responses to a mild redox triggered by H2O2 from the initial state (VO) to an oxidation state (VO1), and are reduced by methionine sulfoxide reductase A to mold the VO' state. It resulted in significantly enhanced enzymolysis efficiency and maximal reaction rates 8.1-fold (VO) and 23.3-fold (VO1) higher than those of the free enzyme. Moreover, cell adhesion was evaluated by the highly selective determination of l-fucose on cell surfaces. Using a combination of chemical oxidation and enzymatic reduction, this work achieves reiterative enzymolysis efficiency regulation of polymer nanoreactors, which has great potential for the construction of redox-responsive nanoreactors and for monitoring cell adhesion.

Polymer-capped gold nanoparticles as nanozymes with improved catalytic activity for the monitoring of serum ciprofloxacin.

More recently, gold nanoparticle (AuNP)-based nanozymes have become one of the burgeoning research hot topics. However, few studies have focused on these AuNP-nanozymes with polymers as ligands. A significant challenge is to reveal their catalytic mechanism and to improve their catalytic activity by changing the structures of the polymers. In this study, polyacrylamide (PAM) with different chain lengths was synthesized and used as the ligand to prepare PAM@AuNPs. The resultant nanozymes exhibited good peroxidase-like activity for catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). In particular, due to the electrostatic interaction between the negatively charged PAM@AuNPs and the positively charged drug, the addition of ciprofloxacin in the oxidation system induced the aggregation of PAM@AuNPs and produced more amount of reactive oxygen species, which greatly promoted the catalytic activity of PAM@AuNPs. Inspired by the attractive property, a highly selective and sensitive colorimetric assay for the monitoring of ciprofloxacin was created. A good linear relationship between the UV-Vis absorption intensity of PAM@AuNPs-TMB-H2O2 at 650 nm wavelength and the ciprofloxacin concentration was observed ranging from 1.0 µM to 12.0 µM (R2 = 0.998), providing the detection limit of 0.5 µM. The ciprofloxacin metabolism was further studied in rats. It reveals great potential of polymer protected AuNP-nanozymes in practical drug analysis.

Poly(N,N-dimethylacrylamide)-stabilized gold nanoparticles as nanozymes with enhancement of catalytic activity for detection of lomefloxacin.

Recently, polymer-protected gold nanoparticles (AuNPs) have attracted extensive attention due to their good catalytic activities. However, how to regulate their catalytic activities by changing the polymer chain morphologies or the interactions between the ligands and the analytes through external stimuli is still a great challenge. This study describes a simple synthesis of AuNPs capped by thermo-responsive poly(N,N-dimethylacrylamide) (PDMAM). In comparison with three kinds of PDMAMs@AuNPs, PDMAM-2@AuNPs exhibited better peroxidase-mimic ability via the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) to generate oxidized TMB (oxTMB). Interestingly, its catalytic activity could be regulated by changing environmental temperature. Importantly, the addition of the antibiotic lomefloxacin endowed the PDMAM-2@AuNPs with enhancement in catalytic efficiency due to electrostatic interactions and the increased levels of reactive oxygen species. Based on this principle, a protocol for highly selective and sensitive monitoring of lomefloxacin has been constructed with the color change from pale blue to deep blue. The ultraviolet-visible absorbance of oxTMB at the wavelength of 650 nm showed a good linear relationship with antibiotic concentration in the range of 0.25-10.0 µM (R2 = 0.990). The limit of detection was 0.1 µM. The practical application of the proposed protocol with the promoted peroxidase-mimic activity for the measurement of lomefloxacin in capsules was realized.

In Situ Determination of Sialic Acid on Cell Surface with a pH-Regulated Polymer Enzyme Nanoreactor.

Sialic acid (SA) is an important monosaccharide that is involved in incurable cancer immunotherapy. However, it is difficult to detect SA in situ using the existing strategy based on the SA-terminated glycopeptide extraction from the cell lysate. The countermeasures of the bottleneck caused by cell disruption and peptide extraction should be designed based on a "cell-surface attachment and controlled enzymolysis" protocol. Herein, a poly(styrene-co-maleic anhydride-acrylic acid-concanavalin A) (PSM-PAA-ConA) was synthesized and developed as a pH-regulated enzyme nanoreactor after being loaded with sialidase and myoglobin. The nanoreactor showed controllable biocatalysis induced by a cascade enzyme reaction and applied for the in situ detection of SA on a living cell surface. The addition of an acidic solution resulted in a decrease in the size of the nanoreactor and enhancement of its permeability, triggering an "on" state of the SA catalysis. Subsequent pH increase led to increased hydrophilicity of the nanoreactor, increasing its size and resulting in the catalytic "off" state. ConA assisted the cell-surface attachment of the enzyme reactor. Furthermore, SA on the surface of living cancer cells was successfully monitored by the pH-regulated enzyme nanoreactor, demonstrating the feasibility of high specificity in situ analysis for SA. This pH-induced catalytic efficiency control by the enzyme nanoreactor provides a potential platform for functional stimuli-responsive catalytic systems as well as a strategy for in situ analysis of biomolecules on the cell surface.

Dual-stimuli-responsive porous polymer enzyme reactor for tuning enzymolysis efficiency.

A strategy for preparing a dual-stimuli-responsive porous polymer membrane enzyme reactor (D-PPMER) is described, consisting of poly (styrene-maleic anhydride-N-isopropylacrylamide-acrylate-3',3'-dimethyl-6-nitro-spiro[2H-1-benzopyran-2,2'-indoline]-1'-esterspiropyran ester) [P(S-M-N-SP)] and D-amino acid oxidase. Tunable control via "on/off" 365 nm UV light irradiation and temperature variation was used to change the membrane surface configuration and adjust the enzymolysis efficiency of the D-PPMER. A chiral capillary electrophoresis technique was developed for evaluation of the enzymatic efficiency of D-PPMER with a Zn(II)-dipeptide complex as the chiral selector and D,L-serine as the substrate. Interestingly, the enzymatic kinetic reaction rate of D-PPMER under UV irradiation at 36 °C (9.2 × 10-2 mM·min-1) was 3.2-fold greater than that of the free enzyme (2.9 × 10-2 mM·min-1). This was because upon UV irradiation at high temperature, the P(SP) and P(N) moieties altered from a "stretched" to a "curled" state to encapsulate the enzyme in smaller cavities. The confinement effect of the cavities further improved the enzymatic efficiency of the D-PPMER. This protocol highlights the outstanding potential of smart polymers, enables tunable control over the kinetic rates of stimuli-responsive enzyme reactors, and establishes a platform for adjusting enzymolysis efficiency using two different stimuli.

Simultaneous Monitoring of Temperature and Ca2+ Concentration Variation by Fluorescent Polymer during Intracellular Heat Production.

The relationship between calcium ion (Ca2+) concentration and temperature variation during the oxidative phosphorylation (OXPHOS) process has become an essential focus for exploration of signaling pathways and neurodegenerative disease. However, there have been limited reports of fluorescent probes for simultaneous Ca2+ detection and temperature sensing. Herein, a new water-soluble fluorescent probe that combines a thermoresponsive polymer, curcumin and Fluo-4 AM for intracelllar temperature and Ca2+ sensing is described. Furthermore, this fluorescent polymer was successfully applied for intracelluar temperature and Ca2+ gradient monitoring generated by exogenous heating in HeLa cells. It was discovered that within 10 min after the OXPHOS process was induced by an inhibitor, the temperature increased 0.5-1.0 °C and the Ca2+ level decreased by about 5.7 µM. These results confirmed that the fluorescent polymer enabled investigation of the relationship between intracelluar temperature and Ca2+-induced neurotransmitter release.

Separation of antipyretic analgesics by open tubular capillary electrochromatography with homopolymer coatings.

This study developed an open-tubular capillary electrochromatography protocol for the analysis of antipyretic analgesic drugs, which used a multifunctional homopolymer as coating. A controlled/living radical polymerization strategy was adopted to obtain poly(N-acryloxysuccinimide) with a tunable chain-length. The homopolymer coating enhanced the separation performance by contributing to the hydrophobic and hydrogen-bonding interactions between the analytes and the homopolymer. The effect of polymer chain-length and buffer pH and concentration on the separation efficiency was evaluated. In this approach, baseline separation of the three test drugs was achieved within 15 min. The repeatability of the prepared homopolymer coating was investigated, with the relative standard deviations < 2.88% observed in intra- and interday runs. Good linearity in the 5-800 µM range (R2 ≥ 0.998) demonstrates that accurate quantitative analysis of real samples was achieved. Moreover, the proposed assay was used to quantify the three drugs (aminopyrine, 4-aminoantipyrine, and phenacetin) in urine samples, achieving recovery rates between 92.1 and 108.7%. This promising methodology may be used for the analysis of drugs in real bio-samples and for the development of unique homopolymer coatings for open-tubular capillary electrochromatography systems.

Non-enzymatic detection of serum glucose using a fluorescent nanopolymer probe.

A fluorescent probe is described for the determination of serum glucose after hepatotoxin-induced liver injury. The probe is based on the use of a water-soluble polymer and has been prepared from a multi-functional azlactone polymer as the linker, amino boronic acid, and Alizarin Red as the signalling moiety. The excitation/emission peaks of the polymeric fluorescent probe are at 468/567 nm. Fluorescence is reduced on addition of glucose. Intensity drops linearly in the 0.1 mM to 14 mM glucose concentration range. The probe was applied to non-enzymatic detection of glucose in rat serum after CCl4-induced liver damage. Graphical abstract A polymer based fluorescent probe has been constructed and applied for non-enzymatic monitoring of serum glucose following hepatotoxin induced liver injury.

Simultaneous Monitoring of Mitochondrial Temperature and ATP Fluctuation Using Fluorescent Probes in Living Cells.

Real-time monitoring of the distribution of energy released during oxidative phosphorylation (OXPHOS) in living cells would advance the understanding of metabolic pathways and cell biology. However, the relationship between intracellular temperature and ATP fluctuation during the OXPHOS process is rarely studied due to the limitation of the sensing approach. Novel fluorescent polymer probes were developed for accurate simultaneous measurements of intracellular temperature and ATP. Utilizing the fluorescence imaging techniques, it was demonstrated for the first time that the temperature in mitochondria increased 2.4 °C and the ATP fluctuation level simultaneously decreased 75% within 2 min during the OXPHOS process. Moreover, the resultant fluorescent polymer probes had good performance and properties for mitochondrial targeting, providing an effective way for investigating mechanisms by which energy is released during the OXPHOS process.

Online Proteolysis and Glycopeptide Enrichment with Thermoresponsive Porous Polymer Membrane Reactors for Nanoflow Liquid Chromatography-Tandem Mass Spectrometry.

In this Article, we have reported a fully automated online method to carry out proteolysis and glycopeptide enrichment in sequence for nanoflow liquid chromatography-tandem mass spectrometry (nLC-ESI-MS/MS) analysis. By implementing two serial thermoresponsive porous polymer membrane reactors (TPPMRs), in which the TPPM could be immobilized either with trypsin for proteolysis or with lectins for glycopeptide enrichment, the entire pretreatment procedure can be performed online in about an hour. The TPPM was fabricated by coating polystyrene-maleic anhydride- N-isopropylacrylamide (PS-MAn-PNIPAm), which was synthesized by reversible addition-fragmentation chain transfer polymerization, on a Nylon sheet. Because of the thermoresponsive nature of PNIPAm, it formed micelle cavities and changed its morphology at elevated temperatures, resulting in enhanced interactions between the enzyme or lectins and the proteins/peptides flowing through the membrane. The performances of the TPPMs were evaluated by varying the temperature conditions and the amount of standard proteins, showing that both proteolysis and glycopeptide enrichment with online deglycosylation were highly efficient at 37 °C. The developed online serial TPPMRs-nLC-ESI-MS/MS method was applied to the human plasma sample (1.5 µL) and a total of 262 N-glycopeptides could be identified from 155 glycoproteins. Thus, the present work demonstrates a fully automated high speed analytical protocol for online proteolysis and glycopeptide enrichment, which is extremely useful for analyzing small amounts of the proteome samples.

Construction of a thermoresponsive magnetic porous polymer membrane enzyme reactor for glutaminase kinetics study.

Fabrication of polymer membranes with nanopores and a confinement effect toward enzyme immobilization has been an enabling endeavor. In the work reported here, an enzyme reactor based on a thermoresponsive magnetic porous block copolymer membrane was designed and constructed. Reversible addition-fragmentation chain transfer polymerization was used to synthesize the block copolymer, poly(maleic anhydride-styrene-N-isopropylacrylamide), with poly(N-isopropylacrylamide) as the thermoresponsive moiety. The self-assembly property of the block copolymer was used for preparation of magnetic porous thin film matrices with iron oxide nanoparticles. By covalent bonding of glutaminase onto the surface of the membrane matrices and changing the temperature to tune the nanopore size, we observed enhanced enzymolysis efficiency due to the confinement effect. The apparent Michaelis-Menten constant and the maximum rate of the enzyme reactor were determined (Km = 32.3 mM, Vmax = 33.3 mM min-1) by a chiral ligand exchange capillary electrochromatography protocol with L-glutamine as the substrate. Compared with free glutaminase in solution, the proposed enzyme reactor exhibits higher enzymolysis efficiency, greater stability, and greater reusability. Furthermore, the enzyme reactor was applied for a glutaminase kinetics study. The tailored pore sizes and the thermoresponsive property of the block copolymer result in the designed porous membrane based enzyme reactor having great potential for high enzymolysis performance. Graphical abstract ᅟ.

Preparation of Polymer@AuNPs with Droplets Approach for Sensing Serum Copper Ions.

A microfluidic droplet synthesis approach for the preparation of poly N-isopropylacrylamide protected gold nanoparticles (PNIPAm@AuNPs) was presented here. Well-dispersed PNIPAm@AuNPs could be generated within 8 min. On the basis of the aggregation-induced UV-vis adsorption intensity increasing mechanism, the PNIPAm@AuNPs-based colorimetric probe displayed high sensitivity and good selectivity for sensing copper ions. A linear calibration of relative UV-vis adsorption intensity increasing versus copper ions concentration was obtained within 5.0-750.0 µM, and the limit of detection was 2.5 µM. Furthermore, after copper ions were injected in rat, a metabolic assay was developed with the proposed probe. The results indicated that the droplet microfluidic synthesis system could provide a new way for preparation of polymer@AuNPs with good polydispersity index and showed great potential of polymer@AuNPs-based sensing probe for application in biological and clinical analysis.

Photoluminescence Lifetime Imaging of Synthesized Proteins in Living Cells Using an Iridium-Alkyne Probe.

Designing probes for real-time imaging of dynamic processes in living cells is a continuous challenge. Herein, a novel near-infrared (NIR) photoluminescence probe having a long lifetime was exploited for photoluminescence lifetime imaging (PLIM) using an iridium-alkyne complex. This probe offers the benefits of deep-red to NIR emission, a long Stokes shift, excellent cell penetration, low cytotoxicity, and good resistance to photobleaching. This example is the first PLIM probe applicable to the click reaction of copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with remarkable lifetime shifts of 414 ns, before and after click reaction. The approach fully eliminates the background interference and distinguishes the reacted probes from the unreacted probes, thus enabling the wash-free imaging of the newly synthesized proteins within single living cells. Based on the unique properties of the iridium complexes, it is anticipated to have applications for imaging other processes within living cells.

Ratiometric Fluorescent Pattern for Sensing Proteins Using Aqueous Polymer-Pyrene/γ-Cyclodextrin Inclusion Complexes.

A ratiometric, versatile, and selective fluorescent pattern to sense and distinguish proteins on the basis of dissociation of aqueous polymer-pyrene/γ-cyclodextrin (γ-CD) inclusion complexes was developed. First, two kinds of aqueous polymer-pyrene were prepared via atom transfer radical polymerization using pyrene functionalized initiator. Then, the pyrene molecules could be accumulated into γ-CD cavity and form polymer-pyrene/γ-CD complexes, resulting in appearance of excimer emissions. The resultant complexes responded to proteins in two ways: nonmetalloproteins binding to polymer component triggered dissociation of the inclusion complexes, accompanied by alteration of pyrene excimer/monomer emission and ratiometric fluorescent intensity changes; the presence of metalloproteins could quench pyrene excimer/monomer emission because of energy transfer. Moreover, the fluorescent responses of the inclusion complexes to different proteins could be modulated by changing polymer type and chain length, resulting in a tunable selectivity and sensitivity. The proposed fluorescent inclusion complexes could provide a promising platform for sensing proteins.

Ratiometric Fluorescent Polymeric Thermometer for Thermogenesis Investigation in Living Cells.

Intracellular temperature has a fundamental effect on cellular events. Herein, a novel fluorescent polymer ratiometric nanothermometer has been developed based on transferrin protein-stabilized gold nanoclusters as the targeting and fluorescent ratiometric unit and the thermosensitve polymer as the temperature sensing unit. The resultant nanothermometer could feature a high and spontaneous uptake into the HeLa cells and the ratiometric temperature sensing over the physiological temperature range. Moreover, the precise temperature sensing for intracellular heat generation in HeLa cells following calcium ions stress has been achieved. This practical intracellular thermometry could eliminate the interference of the intracellular surrounding environment in cancer cells without a microinjection procedure, which is user-friendly. The prepared new nanothermometer can provide tools for unveiling the intrinsic relationship between the intracellular temperature and ion channel function.

Preparation of a novel polymer monolith with functional polymer brushes by two-step atom-transfer radical polymerization for trypsin immobilization.

Novel porous polymer monoliths grafted with poly{oligo[(ethylene glycol) methacrylate]-co-glycidyl methacrylate} brushes were fabricated via two-step atom-transfer radical polymerization and used as a trypsin-based reactor in a continuous flow system. This is the first time that atom-transfer radical polymerization technique was utilized to design and construct polymer monolith bioreactor. The prepared monoliths possessed excellent permeability, providing fast mass transfer for enzymatic reaction. More importantly, surface properties, which were modulated via surface-initiated atom-transfer radical polymerization, were found to have a great effect on bioreactor activities based on Michaelis-Menten studies. Furthermore, three model proteins were digested by the monolith bioreactor to a larger degree within dramatically reduced time (50 s), about 900 times faster than that by free trypsin (12 h). The proposed method provided a platform to prepare porous monoliths with desired surface properties for immobilizing various enzymes.

Preparation of pH-responsive block copolymers for separation of cephalosporin antibiotics by open-tubular capillary electrochromatography.

Stimuli-responsive block copolymers have exhibited their feasibility for drug delivery and analysis of biomolecules. However, study of the electrophoretic behavior of antibiotics by open tubular capillary electrochromatography (OT-CEC) based on smart block copolymers coatings is still a substantial challenge. Herein, we reported an OT-CEC protocol for analysis of cephalosporin antibiotics with pH-responsive block copolymers as coatings. By using the reversible addition-fragmentation chain-transfers radical polymerisation technique, the smart poly(styrene-maleic anhydride-acrylic acid) (P(St-MAn-AA)) was synthesized and subsequently chemical bonded onto the inner walls of amino-grafted capillaries. The pH induced changes in the stretch/curl states of P(St-MAn-AA) chains were used to generate an adjustable hydrophobic/hydrophilic interaction and hydrogen bonds between the polymer coatings and the analytes. The OT-CEC performance was evaluated by varying the monomer ratios, polymer coating amounts and layers, buffer concentrations and pH values. Baseline separation of the three-test antibiotics was achieved at pH 8.0. The proposed OT-CEC technique was further applied to the determination of rat serum antibiotics in the metabolic processes. The present work demonstrates an enhancement in antibiotics separation efficiency, and shows a great potential for the preparation of stimuli-responsive block copolymers coatings and in OT-CEC analysis of real samples in living bio-systems.

Fabrication of Dual-Stimuli-Responsive Polymer Vesicles for Regulation of Enzymolysis Efficiency in A Cascade Reaction.

Enzymatic cascade reactions in confined microenvironments play important roles in cellular chemical transformation. Controlling enzymatic efficiency and eliminating substrate interference in cascade reactions is of great significance. To this end, a vesicle composed of poly(styrene-maleic anhydride-N-isopropylacrylamide)(P(S-M-NIP)) and functionalized with 1,2-bis(10,12- tricosadiynoyl)-sn-glycero-3-phosphocholine (DC89 PC) was designed herein. Based on the thermo-sensitive property of P(S-M-NIP) and the photo-responsive property of DC89 PC, a serial of dual-stimuli-responsive nanoreactors was constructed via enzymes encapsulation to tune their enzymolysis efficiencies. A kinetics study of the glucose oxidase-encapsulated nanoreactor indicated that its enzymolysis velocity increased 2.1- and 1.6-fold under heating and the ultraviolet (UV)-light irradiation, respectively. Consequently, an enzymatic cascade reaction in the proposed enzyme reactor encapsulated with ß-galactosidase and glucose oxidase was investigated. The results revealed a 2.9-fold enhancement in enzymolysis efficiency by changing the ambient temperature under UV irradiation. The dual-stimuli-responsive polymer vesicles could also eliminate H2 O2 interference during the enzymatic cascade reaction. The vesicles demonstrated potential for switch-membrane-permeability, while, the confined microenvironment played a key role in regulating the reactions upon the temperature change and the presence of UV light. Our synthetic multi-organelle-like system provides a new way to mimic the control of cascade reaction catalytic processes by programming the "open/close" sates of the nanocapsules.

Thermo-responsive polymer-modified metal-organic frameworks as soft-rigid enzyme-reactors for enhancement of enzymolysis efficiency using a controllable embedding protocol.

Enzyme immobilization is a suitable strategy to promote biosensing, biocatalysis and the industrial applications of biomacromolecules. Although considerable efforts have been devoted to the construction of metal-organic frameworks (MOFs)-based porous nano-reactors, their enzymolysis efficiency cannot be tuned by varying the external conditions due to the fixed conformation of the encapsulated enzymes. In this work, a controllable embedding protocol was developed based on the concept of stimuli-responsive polymer modified MOFs. Using MOFs as a rigid template for thermo-responsive polymer modification and consequently utilizing the polymer-MOFs complexes for enzyme (glucose oxidase, horseradish peroxidase, trypsin, cytochrome c, glutaminase) immobilization, different porous nano-reactors were fabricated. Most importantly, the polymer on the MOF surface exhibited good ability to form a "soft nest" at high temperature for inducing the confinement effect and further improving the enzymolysis efficiencies of the nano-reactors 3.75-37.7-fold. Moreover, a colorimetric sensing method was developed to detect serum glucose with the proposed nano-reactors. This strategy is highly versatile and suitable for diverse rigid MOFs modified with stimuli-responsive soft-polymer-nests and enzymes.