Nontargeted Analysis of Reactive Nitrogenous Compounds in Suwannee River Standard Reference Materials and Authentic River Water Samples.

Concerns over toxic nitrogenous disinfection byproducts (N-DBPs) necessitate identifying their precursors in source water. Natural organic amino compounds are known precursors to N-DBPs. Three Suwannee River (SR) standard reference materials (SRMs), humic acids (HA), fulvic acids (FA), and natural organic matter (NOM), are commonly used to study DBP formation, but the chemical makeup of amino compounds in SRSRMs remains largely unknown. To address this, we combined stable hydrogen/deuterium isotope labeling, HDPairFinder bioinformatics, and nontargeted high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) to characterize these compounds in SRSRMs. This method classifies reactive amines, provides accurate masses and MS/MS spectra, and quantifies intensities. We identified 2707 high-quality features with primary and/or secondary amines in SRSRMs and 75% of them having an m/z < 300. Across all three SRSRMs, 327 amino features were detected, while 856, 794, and 200 unique features were found in SRNOM, SRHA, and SRFA, respectively. In North Saskatchewan River (NSR) samples, a total of 6449 amino features were detected, 818 of them matched those in SRSRMs, and 87% of them were different between the two rivers. Using chemical standards, we confirmed 10 compounds and tentatively identified 5 more. This study highlights similarities and differences in reactive N-precursors in SRSRMs and local river water, enhancing the understanding of geo-differences in reactive N-precursors in different source waters.

Light-degradable nanocomposite hydrogels for antibacterial wound dressing applications.

Skin injuries infected by bacteria can cause life-threatening human diseases if not treated properly. In this work, we developed a light-degradable nanocomposite hydrogel to achieve both controlled antibiotic delivery and hydrogel degradation using light as the sole stimulus. Specifically, we incorporated triclosan-loaded, poly(N-isopropylacrylamide)-based nanogels (TCS-NGs) that exhibited potent antibacterial efficacy, into a light-degradable poly (ethylene glycol) (PEG)-based hydrogel matrix via simple physical entrapment method. Upon exposure to 365 nm light, the hydrogel matrix could rapidly degrade, which subsequently released the entrapped TCS-NGs into the surrounding environment. Our results demonstrated that TCS-NGs released from light-degradable nanocomposite hydrogels still possessed remarkable antibacterial efficacy by inhibiting the growth of Staphylococcus aureus both in solution (a fivefold reduction in optical density compared to the blank control) and on bacteria-infected porcine skins (a fivefold reduction in colony-forming units compared to the blank control). Finally, using an alamarBlue assay on human dermal fibroblasts, we determined that each component of the nanocomposite hydrogel exhibited excellent biocompatibility (>90% cell viability) and would not cause significant cytotoxicity. Overall, the fabricated light-degradable nanocomposite hydrogels could serve as novel material for antibacterial wound dressing applications.

ChloroDBPFinder: Machine Learning-Guided Recognition of Chlorinated Disinfection Byproducts from Nontargeted LC-HRMS Analysis.

High-resolution mass spectrometry (HRMS) is a prominent analytical tool that characterizes chlorinated disinfection byproducts (Cl-DBPs) in an unbiased manner. Due to the diversity of chemicals, complex background signals, and the inherent analytical fluctuations of HRMS, conventional isotopic pattern (37Cl/35Cl), mass defect, and direct molecular formula (MF) prediction are insufficient for accurate recognition of the diverse Cl-DBPs in real environmental samples. This work proposes a novel strategy to recognize Cl-containing chemicals based on machine learning. Our hierarchical machine learning framework has two random forest-based models: the first layer is a binary classifier to recognize Cl-containing chemicals, and the second layer is a multiclass classifier to annotate the number of Cl present. This model was trained using ∼1.4 million distinctive MFs from PubChem. Evaluated on over 14,000 unique MFs from NIST20, this machine learning model achieved 93.3% accuracy in recognizing Cl-containing MFs (Cl-MFs) and 92.9% accuracy in annotating the number of Cl for Cl-MFs. Furthermore, the trained model was integrated into ChloroDBPFinder, a standalone R package for the streamlined processing of LC-HRMS data and annotating both known and unknown Cl-containing compounds. Tested on existing Cl-DBP data sets related to aspartame chlorination in tap water, our ChloroDBPFinder efficiently extracted 159 Cl-containing DBP features and tentatively annotated the structures of 10 Cl-DBPs via molecular networking. In another application of a chlorinated humic substance, ChloroDBPFinder extracted 79 high-quality Cl-DBPs and tentatively annotated six compounds. In summary, our proposed machine learning strategy and the developed ChloroDBPFinder provide an advanced solution to identifying Cl-containing compounds in nontargeted analysis of water samples. It is freely available on GitHub (https://github.com/HuanLab/ChloroDBPFinder).

Microgel-based etalon immunoassay for IgG detection.

We developed an immunoassay for mouse immunoglobulin (IgG) quantitation using poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAm-co-AAc) microgel-based etalon devices. To achieve this, a biotinylated primary antibody specific to mouse IgG was immobilized on the top Au layer of an etalon device via its interaction with a streptavidin-modified etalon surface. Mouse IgG captured on the etalon surface from the solution was quantified using an HRP-conjugated secondary antibody. HRP catalyzed the oxidation of 4-chloro-1-naphthol (4CN) to form insoluble 4-chloro-1-naphthon (4CNP), resulting in a concentration change of 4CN in solution. The etalon was able to detect the 4CN concentration change by monitoring the extent of the etalon's reflectance peak shift, which allows the quantitation of mouse IgG. The etalon-based assay can detect mouse IgG down to 0.018 nM with a linear range of 0.02-5 nM.

Bovine Serum Albumin-Protected Gold Nanoclusters for Sensing of SARS-CoV-2 Antibodies and Virus.

An approach to assess severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (and past infection) was developed. For virus detection, the SARS-CoV-2 virus nucleocapsid protein (NP) was targeted. To detect the NP, antibodies were immobilized on magnetic beads to capture the NPs, which were subsequently detected using rabbit anti-SARS-CoV-2 nucleocapsid antibodies and alkaline phosphatase (AP)-conjugated anti-rabbit antibodies. A similar approach was used to assess SARS-CoV-2-neutralizing antibody levels by capturing spike receptor-binding domain (RBD)-specific antibodies utilizing RBD protein-modified magnetic beads and detecting them using AP-conjugated anti-human IgG antibodies. The sensing mechanism for both assays is based on cysteamine etching-induced fluorescence quenching of bovine serum albumin-protected gold nanoclusters where cysteamine is generated in proportion to the amount of either SARS-CoV-2 virus or anti-SARS-CoV-2 receptor-binding domain-specific immunoglobulin antibodies (anti-RBD IgG antibodies). High sensitivity can be achieved in 5 h 15 min for the anti-RBD IgG antibody detection and 6 h 15 min for virus detection, although the assay can be run in "rapid" mode, which takes 1 h 45 min for the anti-RBD IgG antibody detection and 3 h 15 min for the virus. By spiking the anti-RBD IgG antibodies and virus in serum and saliva, we demonstrate that the assay can detect the anti-RBD IgG antibodies with a limit of detection (LOD) of 4.0 and 2.0 ng/mL in serum and saliva, respectively. For the virus, we can achieve an LOD of 8.5 × 105 RNA copies/mL and 8.8 × 105 RNA copies/mL in serum and saliva, respectively. Interestingly, this assay can be easily modified to detect myriad analytes of interest.

Utilization of a Glucometer Test Strip and Enzymatic Reactions to Quantify Anti-SARS-CoV-2 Spike RBD IgG Antibody and SARS-CoV-2 Virus in Saliva and Serum.

A sensor capable of quantifying both anti-SARS-CoV-2 spike receptor-binding domain (RBD) antibody levels and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in saliva and serum was developed. This was accomplished by exploiting the enzymatic reaction of maltose and orthophosphate (PO43-) in the presence of maltose phosphorylase to generate an equivalent amount of glucose that was detected using a commercial glucometer test strip and a potentiostat. Important for this approach is the ability to generate PO43- in an amount that is directly related to the concentration of the analytes. RBD-modified magnetic microparticles were used to capture anti-SARS-CoV-2 spike RBD antibodies, while particles modified with anti-SARS-CoV-2 nucleocapsid antibodies were used to capture SARS-CoV-2 nucleocapsid protein from inactivated virus samples. A magnet was used to isolate and purify the magnetic microparticles (with analyte attached), and alkaline phosphatase-conjugated secondary antibodies were bound to the analytes attached to the respective magnetic microparticles. Finally, through enzymatic reactions, specific amounts of PO43- (and subsequently glucose) were generated in proportion to the analyte concentration, which was then quantified using a commercial glucometer test strip. Utilizing glucose test strips makes the sensor relatively inexpensive, with a cost per test of ∼US $7 and ∼US $12 for quantifying anti-SARS-CoV-2 spike RBD antibody and SARS-CoV-2, respectively. Our sensor exhibited a limit of detection of 0.42 ng/mL for anti-SARS-CoV-2 spike RBD antibody, which is sensitive enough to quantify typical concentrations of antibodies in COVID-19-infected or vaccinated individuals (>1 µg/mL). The limit of detection for the SARS-CoV-2 virus is 300 pfu/mL (5.4 × 106 RNA copies/mL), which exceeds the performance recommended by the WHO (500 pfu/mL). In addition, the sensor exhibited good selectivity when challenged with competing analytes and could be used to quantify analytes in saliva and serum matrices with an accuracy of >94% compared to RT-qPCR.

TP63 Functions as a Tumor Suppressor Regulated by GAS5/miR-221-3p Signaling Axis in Human Non-Small Cell Lung Cancer Cells.

Background: Tumor protein p63 (TP63) has been proven to play a role as a tumor suppressor in some human cancers, including non-small cell lung cancer (NSCLC). This study aimed to investigate the mechanism of TP63 and analyze the underlying pathway dysregulating TP63 in NSCLC. Methods: RT-qPCR and Western blotting assays were used to determine gene expression in NSCLC cells. The luciferase reporter assay was performed to explore the transcriptional regulation. Flow cytometry was used to analyze the cell cycle and cell apoptosis. Transwell and CCK-8 assays were performed to test cell invasion and cell proliferation, respectively. Results: GAS5 interacted with miR-221-3p, and its expression was significantly reduced in NSCLC. GAS5, as a molecular sponge, upregulated the mRNA and protein levels of TP63 by inhibiting miR-221-3p in NSCLC cells. The upregulation of GAS5 inhibited cell proliferation, apoptosis, and invasion, which was partially reversed by the knockdown of TP63. Interestingly, we found that GAS5-induced TP63 upregulation promoted tumor chemotherapeutic sensitivity to cisplatin therapy in vivo and in vitro. Conclusion: Our results revealed the mechanism by which GAS5 interacts with miR-221-3p to regulate TP63, and targeting GAS5/miR-221-3p/TP63 may be a potential therapeutic strategy for NSCLC cells.

TFAP4 Activates IGF2BP1 and Promotes Progression of Non-Small Cell Lung Cancer by Stabilizing TK1 Expression through m6A Modification.

Non-small cell lung cancer (NSCLC) is a well-known global health concern. TFAP4 has been reported to function as an oncogene. This study sought to investigate the molecular mechanism of TFAP4 in NSCLC development. Significantly highly-expressed gene IGF2BP1 was screened on online databases and its downstream gene TK1 was predicted. IGF2BP1 promoter sequence was identified. The binding site of TFAP4 and IGF2BP1 was predicted. The expression correlations among TFAP4, IGF2BP1, and TK1 were confirmed. The correlations between TFAP4, IGF2BP1, TK1, and NSCLC prognosis were predicted. NSCLC and paracancerous tissues were collected. The expressions of TFAP4, IGF2BP1, and TK1 were detected. NSCLC cell proliferation, migration, invasion, and apoptosis were detected. The binding of TFAP4 to the IGF2BP1 promoter was verified. m6A modification of TK1 mRNA was detected. The correlation between IGF2BP1 and TK1 was confirmed. A subcutaneous tumor xenograft model was established to validate the effect of TFAP4 in vivo. IGF2BP1 was highly expressed in NSCLC tissues and cells. IGF2BP1 knockdown repressed NSCLC cell proliferation, migration, and invasion and facilitated apoptosis. Mechanically, TFAP4 transcriptionally activated IGF2BP1. IGF2BP1 stabilized TK1 expression via m6A modification and promoted NSCLC cell proliferation, migration, and invasion. In vivo experiments confirmed that TFAP4 knockdown suppressed tumor growth by downregulating IGF2BP1/TK1. IMPLICATIONS: Our findings revealed that TFAP4 activated IGF2BP1 and facilitated NSCLC progression by stabilizing TK1 expression via m6A modification, which offered new insights into the diagnosis and treatment of NSCLC.

LINC01342 silencing upregulates microRNA-508-5p to inhibit progression of lung cancer by reducing cysteine-rich secretory protein 3.

Long noncoding RNAs (lncRNAs) are critical players during cancer progression. Nevertheless, the effect of most lncRNAs in lung cancer (LC) remains unclear. We aimed to explore the role of LINC01342 in LC development through the microRNA-508-5p (miR-508-5p)/cysteine-rich secretory protein 3 (CRISP3) axis. LINC01342, miR-508-5p, and CRISP3 expression in clinical samples and cell lines were determined, and their correlations in LC were analyzed. The prognostic role of LINC01342 in LC patients was evaluated. LC cells were screened and, respectively, transfected to alter the expression of LINC01342, miR-508-5p, and CRISP3. Then, proliferation, migration, invasion, and apoptosis of transfected LC cells were determined, and the in vivo tumor growth was observed as well. Binding relationships between LINC01342 and miR-508-5p, and between miR-508-5p and CRISP3 were identified. LINC01342 and CRISP3 were upregulated and miR-508-5p was downregulated in LC tissues and cells. High LINC01342 expression indicated a poor prognosis of LC patients. The LINC01342/CRISP3 silencing or miR-508-5p elevation inhibited proliferation, migration, and invasion of LC cells and promoted LC cell apoptosis, and also suppressed the in vivo tumor growth. LINC01342 bound to miR-508-5p and miR-508-5p targeted CRISP3. LINC01342 plays a prognostic role in LC and LINC01342 silencing upregulates miR-508-5p to inhibit the progression of LC by reducing CRISP3.

LINC01503/miR-342-3p facilitates malignancy in non-small-cell lung cancer cells via regulating LASP1.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the major types of lung cancer, which is a prevalent human disease all over the world. LncRNA LINC01503 is a super-enhancer-driven long non-coding RNA that is dysregulated in several types of human cancer. However, its role in NSCLC remains unknown. METHODS: Thirty NSCLC patients were recruited between April 2012 and April 2016. Luciferase reporter assay, qRT-PCR, Cell Counting Kit-8 (CCK-8), Transwell migration assay, RNA pull-down assay, western blotting, 5-ethynyl-29-deoxyuridine (EdU) assays, and flow cytometry were utilized to characterize the roles and relationships among LINC01503, miR-342-3p, and LASP1 in NSCLC. The transplanted mouse model was built to examine their biological functions in vivo. RESULTS: We demonstrated that the expression of lncRNA LINC01503 and LIM and SH3 domain protein 1 (LASP1) were upregulated and miR-342-3p was downregulated in NSCLC samples and cell lines. Functional experiments revealed that inhibiting the expression of LINC01503 or over-expression of miR-342-3p inhibited NSCLC growth and metastasis both in vitro and in vivo. In addition, LINC01503 could bind to miR-342-3p and affect the expression of LASP1. CONCLUSION: These results provide a comprehensive analysis of the roles of LINC01503 as a competing endogenous RNA (ceRNA) in NSCLC progression.

Long non­coding RNA LUCAT1 contributes to cisplatin resistance by regulating the miR­514a­3p/ULK1 axis in human non­small cell lung cancer.

Drug resistance is a major obstacle in the therapy of malignant tumors, including non­small cell lung cancer (NSCLC). Long non­coding RNAs (lncRNAs) have been demonstrated to be involved in chemoresistance. The present study aimed to investigate the role of lung cancer­associated transcript 1 (LUCAT1) in cisplatin (DDP) resistance in NSCLC. By using reverse transcription­quantitative polymerase chain reaction (RT­qPCR), it was found that the expression of LUCAT1 was elevated and that of microRNA­514a­3p (miR­514a­3p) was decreased in DDP­resistant NSCLC tissues and cells. Functionally, LUCAT1 upregulation enhanced cisplatin resistance by promoting the viability, autophagy and metastasis, and inhibiting the apoptosis of NSCLC cells, as demonstrated by Cell Counting kit­8 (CCK­8) assay, western blot analysis, Transwell assay and flow cytometric analysis. LUCAT1 was identified as a sponge of miR­514a­3p and uncoordinated­51­like kinase 1 (ULK1) was proven to be a target gene of miR­514a­3p by bioinformatics analysis, dual­luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The enhancing effect of miR­514a­3p on cisplatin sensitivity was reversed by the elevation of LUCAT1. ULK1 knockdown suppressed cisplatin resistance, while this effect was attenuated by miR­514a­3p inhibition. Moreover, LUCAT1 positively regulated ULK1 expression by targeting miR­514a­3p. In addition, LUCAT1 knockdown suppressed tumor growth in vivo. On the whole, the findings of the present study demonstrate that LUCAT1 contributes to the resistance of NSCLC cells to cisplatin by regulating the miR­514a­3p/ULK1 axis, elucidating a novel regulatory network in cisplatin resistance in NSCLC.

Stimuli-responsive polymer/nanomaterial hybrids for sensing applications.

Chemical and biological/biochemical sensors are capable of generating readout signals that are proportional to the concentration of specific analytes of interest. Signal sensitivity and limit of detection/quantitation can be enhanced through the use of polymers, nanomaterials, and their hybrids. Of particular interest are stimuli-responsive polymers and nanomaterials due to their ability to change their physical and/or chemical characteristics in response to their environment, and/or in the presence of molecular/biomolecular species of interest. Their individual use for sensing applications have many benefits, although this review focuses on the utility of stimuli-responsive polymer and nanomaterial hybrids. We discuss three main topics: stimuli-responsive nanogels, stimuli-responsive network polymers doped with nanomaterials, and nanoparticles modified with stimuli-responsive polymers.

Stimuli-responsive polymer-based systems for diagnostic applications.

Stimuli-responsive polymers exhibit properties that make them ideal candidates for biosensing and molecular diagnostics. Through rational design of polymer composition combined with new polymer functionalization and synthetic strategies, polymers with myriad responsivities, e.g., responses to temperature, pH, biomolecules, CO2, light, and electricity can be achieved. When these polymers are specifically designed to respond to biomarkers, stimuli-responsive devices/probes, capable of recognizing and transducing analyte signals, can be used to diagnose and treat disease. In this review, we highlight recent state-of-the-art examples of stimuli-responsive polymer-based systems for biosensing and bioimaging.

MARCH9 Suppresses Lung Adenocarcinoma Progression by Downregulating ICAM-1.

BACKGROUND/AIMS: To investigate the clinical significance and functional mechanisms of membrane-associated RING-CH protein 9 (MARCH9) in lung adenocarcinoma (LAC). METHODS: Immunohistochemistry staining was performed to explore the expression of MARCH9 in LAC tissues and adjacent normal lung tissues. Patients' prognosis was evaluated using overall survival. The prognostic role of MARCH9 was tested with univariate and multivariate analyses. To confirm the effect of MARCH9 in cell proliferation and invasion, overexpression of MARCH9 was induced in two LAC cell lines. Cell cycle, apoptosis, migration, invasion, and immunoprecipitation experiments were performed to further explore the signaling pathways involved. RESULTS: Analysis of a series of 143 clinical samples revealed that MARCH9 was down-regulated in tumor tissues compared with normal lung tissues, and this was closely associated with lymph node metastasis (P = 0.004). Univariate and multivariate analyses indicated that MARCH9 was an independent prognostic biomarker for LAC; low MARCH9 expression indicated poor overall survival. Cellular studies with A549 and H1299 cells demonstrated that MARCH9 can attenuate tumor migration and invasion but had little effect on cell cycle or apoptosis. Moreover, an interaction between MARCH9 and ICAM-1 protein was identified, and overexpression of MARCH9 was found to attenuate the oncogenic effect of ICAM-1, suggesting that MARCH9 may inhibit tumor progression by downregulating ICAM-1 signaling. CONCLUSION: MARCH9 downregulation in LAC tissues correlated with poor clinical outcomes. MARCH9 may serve as a novel biomarker and potential therapeutic target for LAC.

Effect of exogenous p51a gene on the growth and chemo sensitivity of human lung adenocarcinoma cell lines.

BACKGROUND: The dysfunction of p53-mediated apoptosis is the key to tumorigenesis, so most gene therapy programs concentrate on improving the expressing level of wild-type p53 in tumour cells. However, the p53 gene therapy has not yielded satisfactory results in tumours with normal p53 function. A new member of p53 gene family-p63, has provided new hopes. TAp63γ (p51A) resembles p53 the most, thus it might become a new promising therapeutic gene of tumours. METHODS: We designed the primer pairs of p51A and amplified the p51A cDNA sequence from human skeletal muscle poly A + RNA to construct recombinant plasmid. It was then transfected into human lung adenocarcinoma cell lines A549 and NCI-H1299. RT-PCR, Western blot, MTT, flow cytometry and colony formation assay were used to analyse the growth and chemosensitivity of tumour cells. RESULTS: The recombinant plasmid was constructed and transfected into tumour cells successfully. After transfection, p51A mRNA, P51A protein and P21 protein level raised significantly. Cell proliferation capacity and colony formation rate decreased while cell apoptosis rate and chemosensitivity to cisplatin and adriamycin increased significantly. CONCLUSIONS: Exogenous p51A gene can increase its expression in A549 and NCI-H1299 cells, suppress cell growth and induce cell apoptosis. Moreover, it can also cooperate with chemotherapy and reduce the dose and side-effect. p51A gene can suppress tumours in spite of p53 status and p21 gene might be involved. It might become a new promising therapeutic gene of tumours, which will make up for the limitation of p53 gene therapy.

The lncRNA RHPN1-AS1 downregulation promotes gefitinib resistance by targeting miR-299-3p/TNFSF12 pathway in NSCLC.

Although epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) gefitinib has exhibited notable clinical efficacy in non-small cell lung cancer (NSCLC) patients. However, its therapeutic efficacy is ultimately limited by the development of gefitinib resistance. The present study aimed to investigate the effects of the long non-coding RNA, RHPN1-AS1 on gefitinib resistance in NSCLC and explore the underlying mechanisms. In this study, RHPN1-AS1 was observed to be downregulated in gefitinib resistant patients and NSCLC cell lines. Besides, decreased expression of RHPN1-AS1 was found to be associated with poor prognosis of NSCLC patients. RHPN1-AS1 knockdown conferred gefitinib resistance to gefitinib sensitive NSCLC cells, whereas the overexpression of RHPN1-AS1 sensitized gefitinib resistant NSCLC cells to gefitinib treatment. Mechanistically, RHPN1-AS1 was found to positively regulate the expression of TNFSF12 by directly interacting with miR-299-3p. Collectively, RHPN1-AS1 modulates gefitinib resistance through miR-299-3p/TNFSF12 pathway in NSCLC. Our findings indicate that RHPN1-AS1 may serve as not only a prognostic biomarker for gefitinib resistance but also as a promising therapeutic biomarker and target for the treatment of NSCLC patients.

Silver nanoparticle-loaded microgel-based etalons for H2O2 sensing.

Silver nanoparticles (AgNPs) were generated inside the network structure of poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-AAc) microgels that were sandwiched between two thin Au layers (15 nm) of an etalon. This was done by introducing Ag+ to the etalons composed of deprotonated microgels, followed by its subsequent reduction with NaBH4. The resultant microgels were collected and then characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), verifying the loading of AgNPs with relatively uniform diameter (5-7 nm) within the microgels. Furthermore, the optical properties of the resultant etalons and their response to H2O2 were evaluated by reflectance spectroscopy. Specifically, upon the addition of H2O2, the AgNP-loaded etalons exhibited both a red shift in the position of the reflectance peaks and an increase in reflected wavelength intensity. We hypothesize that the dual signal response of the devices was a result of oxidative decomposition of the AgNPs, enabling the microgels to swell and for more light to be reflected (due to the loss of the light absorbing AgNPs). Finally, we showed that the AgNPs could be regenerated in the used etalons multiple times without a loss in performance. This work provides a cost-effective means to detect H2O2, which could be modified to sense a variety of other species of physiological and environmental importance through rationally loading other functional nanomaterials.