Formaldehyde Research Articles

Strategija za ocjenjivanje učinka formaldehida u anatomskom patološkom laboratoriju treći dio

To date, formaldehyde (FA) is one of the more common chemicals and its use is widespread around the world in different sectors, especially in chemical facilities and health care. FA is widely used in working activities owing to its chemical and physical properties. However, it also represents a concerning hazard for the workers’ health due to its toxicity and recognized carcinogenicity. The FA exposure evaluation in occupational setting has arisen interest in the scientific community that leads to the development of several analytical instruments in order to assess both long term and short-term exposure. The paper presents and discusses an equivalence tests procedure via the 2.4-dinitrophenylhydrazine (DNPH)-active air sampling formaldehyde (FA) reference method and two non-reference instruments based on continuous, direct reading monitoring, namely ProCeas® (AP2E) and NEMo XT (Ethera). The FA standard atmosphere calibration system was used to check the reference method by Pearson’s test. Subsequently, the Passing-Bablok test was carried out between the non-reference methods and the DNPH method for potential systematic or proportional errors, and finally the Bland-Altman plot was applied to determine the mean bias and the variances of the recorded values by the reference and non-reference methods in on-field sampling. The results showed a good correlation between the non-references method and the DNPH ones, suggesting their possible applications in heterogeneous occupational scenarios.

Si-rhodamines with fine-tuned reactivities for tracking formaldehyde in glioblastoma

Formaldehyde (FA), an essential signaling molecule and an emerging neurotoxin in the brain, regulates various physiological and pathological processes. The abnormal metabolism of FA is associated with extensive brain diseases, including glioblastoma. However, FA probes with systematically fine-tuned reactivities are still very challenging. A group of silicon-substituted rhodamine-based FA probes was designed with fine-tuned structures and FA activities for tracking FA in vivo. With systematic structural manipulation, we have quantitatively revealed the chemical origins of the distinct FA reactivities in probes. Moreover, we successfully tracked the dynamic of FA in live cells, organs, and live animals by the designed probe. The vivid upregulation of FA in heterotopic xenografted and orthotopic glioblastoma by fluorescence imaging with the designed FA probe has proved that FA can be a potential molecular marker for glioblastoma.

A green and moderate approach for the synthesis of methyl formate via dimethoxymethane disproportionation over H-zeolites

Methyl formate (MF) is an important building block in the modern chemical industry, primarily produced through homogeneous carbonylation of methanol under harsh reaction conditions. It is of great interest but remains challenges to develop new heterogeneous catalytic system under mild reaction conditions to replace the homogeneous route. Herein, we report an efficient and green strategy for MF production by dimethoxymethane (DMM) disproportionation over acidic zeolites. Up to nearly100 % DMM conversion and 0.76 g gcat−1 h−1 of MF space time yield (STY) is achieved over H-SSZ-13 under moderate conditions of 0.1 MPa and 393 K. Moreover, H-SSZ-13 shows superior stability during a 100 h continuous test. Combined with multiple characterizations, formaldehyde (FA) has been proved to be a crucial precursor for the formation of MF and the complete mechanism is proposed. This strategy provides a new and feasible approach for continuous large-scale MF production using acidic zeolite as catalyst by heterogeneous catalytic systems.

Coking and deactivation behavior study of Ce-modified Cs-Nb/Al2O3 in aldol condensation of methyl propionate with formaldehyde

Coke deposition during the aldol condensation of methyl propionate (MP) and formaldehyde (FA) to produce methyl methacrylate (MMA) is a critical factor limiting the long-term stability of catalysts. In this work, Ce-modified Cs-Nb/Al2O3 catalysts with superior catalytic activity and robust coke resistance were achieved during the reaction by enhancing the oxygen vacancy (OV) ratio. With optimal Ce loading of 1 %, the MP conversion of 35.4 % and MMA selectivity of 90.3 % can be achieved. Meanwhile, the coke content of the modified catalyst significantly reduced from the original 10.49 wt% to 5.44 wt%. It was discovered that higher water content in the reaction feedstock promotes the hydrolysis reaction, resulting in a decrease in MMA selectivity. Furthermore, the presence of water can promote the conversion of Lewis acid sites to Brønsted acid sites, while an excess of Brønsted acid sites can accelerate the coke formation. Various characterization techniques confirmed that the coke species on the used catalysts consisted basically of polycyclic aromatic hydrocarbons and aliphatic compounds. Ultimately, the kinetics of coke deposition on Cs-Nb/Al2O3 and Cs-Nb-1Ce/Al2O3 were established using the modified Voorhies equation, offering a reliable method to predict coke accumulation under specific conditions. The higher apparent activation energy of coke formation observed on Cs-Nb-1Ce/Al2O3 is responsible for its robust coke resistance.

Distinct DNA repair mechanisms prevent formaldehyde toxicity during development, reproductionand aging.

Formaldehyde (FA) is a recognized environmental and metabolic toxin implicated in cancer development and aging. Inherited mutations in the FA-detoxifying enzymes ADH5 and ALDH2 genes lead to FA overload in the severe multisystem AMeD syndrome. FA accumulation causes genome damage including DNA-protein-, inter- and intra-strand crosslinks and oxidative lesions. However, the influence of distinct DNA repair systems on organismal FA resistance remains elusive. We have here investigated the consequence of a range of DNA repair mutants in a model of endogenous FA overload generated by downregulating the orthologs of human ADH5 and ALDH2 in C. elegans. We have focused on the distinct components of nucleotide excision repair (NER) during developmental growth, reproduction and aging. Our results reveal three distinct modes of repair of FA-induced DNA damage: Transcription-coupled repair (TCR) operating NER-independently during developmental growth or through NER during adulthood, and, in concert with global-genome (GG-) NER, in the germline and early embryonic development. Additionally, we show that the Cockayne syndrome B (CSB) factor is involved in the resolution of FA-induced DNA-protein crosslinks, and that the antioxidant and FA quencher N-acetyl-l-cysteine (NAC) reverses the sensitivity of detoxification and DNA repair defects during development, suggesting a therapeutic intervention to revert FA-pathogenic consequences.

Water-soluble polymeric probe with tryptophan pendants for formaldehyde sensing

Formaldehyde (FA) is a grade-I carcinogen and the most reactive aldehyde in the carbonyl family, posing substantial health hazards. Herein, a water-soluble polymeric probe with side-chain tryptophan pendants is proposed that relies on an FA-induced Pictet-Spengler reaction for FA sensing in an aqueous medium. The polymeric probe shows cyan fluorescence in an aqueous medium after the interaction with FA due to the formation of a β-carboline derivative, confirmed by high-resolution mass spectrum analysis of the product from the model reaction between tryptophan methyl ester and FA. The copolymer’s sensitivity to FA in aqueous solutions at the nanomolar level is estimated using the fluorescence titration method, where ∼20-fold enhancement in fluorescence intensity is observed within 2 min when 200 µM FA is added to the aqueous solution of the copolymer. The probe can selectively detect FA using colorimetric and fluorometric methods with a detection limit as low as 25 nM. The FA-sensing mechanism is studied from the model reaction of tryptophan methyl ester (TME) with FA, and density functional theory (DFT).

A highly sensitive Golgi-targeted fluorescent probe for the simultaneous detection of malondialdehyde and formaldehyde in living systems and foods

Malondialdehyde (MDA) and formaldehyde (FA) are highly active carbonyl substances widely present in both biological and abiotic systems. The detection of MDA and FA is of great significance for disease diagnosis and food safety monitoring. However, due to the similarity in structural properties between MDA and FA, very few probes for synergistically detecting MDA and FA were reported. In addition, functional abnormalities in the Golgi apparatus are closely related to MDA and FA, but currently there are no fluorescent probes that can detect MDA and FA in the Golgi apparatus. Therefore, we constructed a simple Golgi-targetable fluorescent probe GHA based on hydrazine moiety as the recognition site to produce a pyrazole structure after reaction with MDA and to generate a CN double bond after reaction with FA, allowing MDA and FA to be distinguished due to different emission wavelengths during the recognition process. The probe GHA has good specificity and sensitivity. Under the excitation of 350 nm, the blue fluorescence was significantly enhanced at 424 nm when the probe reacted with MDA, and the detection limit was 71 nM. At the same time, under the same excitation of 350 nm, the reaction with FA showed a significant enhancement of green fluorescence at 520 nm, with a detection limit of 12 nM for FA. And the simultaneous and high-resolution imaging of MDA and FA in the Golgi apparatus of cells was achieved. In addition, the applications of the probe GHA in food demonstrated it can provide a powerful method for food safety monitoring. In summary, this study offers a promising tool for the synergistic identification and determination of MDA and FA in the biosystem and food, facilitating the revelation of their detailed functions in Golgi apparatus and the monitoring of food safety.

Genotoxicity of Formaldehyde: Effect of Whole-Body Exposure on Polychromatic Erythrocyte/Normochromatic Erythrocyte Ratio in Male and Female Rats.

Every day, millions of individuals are exposed to formaldehyde (FA) due to its extensive presence and versatile use. Many in vivoand in vitroexperiments revealed that the mechanism of genotoxicity induced by FA exposure is complex yet toxicity upon whole-body exposure (WBE) to FA is less. As teachers, students, and skilled assistants in the health care sectors are also extensively exposed to FA vapors, it might result in genotoxicity. However, the effects of subchronic exposure to FA at low concentrations are not clear. Hence, analysis of the micronucleus (MN) was necessary to study the genetic toxicity triggered by FA in the bone marrow of male and female experimental rats. The present study is a gender- and duration of exposure-based assessment of the geno- and cytotoxicity in bone marrow cells of Wistar rats to study the effect of WBE to 10% FA on polychromatic erythrocytes/normochromatic erythrocytes (PCE/NCE) ratio and micronucleated polychromatic erythrocytes (MnPCE) in experimental rats. The obtained result clearly showed that WBE to FA for 60 days at concentrations between 1 and 1.1 ppm (0, 1, and 1.5 h) induced genotoxic effects in both male and female rats by altering the MnPCE% and significantly increasing the ratio of PCE/NCE (1.07 ± 0.23, 1.20 ± 0.20, 1.22 ± 0.14). The PCE/NCE ratio in male rats was lesser (0.98, 1.12, and 1.18) when compared with female rats (1.17, 1.29, and 1.26) with 0, 1, and 1.5 h exposure, respectively. Thus, the genetic/cellular sensitivity to FA differs among the sexes and also depends on the exposure duration.

Tuning strategies of MIL metal organic frameworks for adsorptive removal of formaldehyde in air

Materials Institute Lavoisier (MIL) metal organic frameworks (MOFs) are known for their potential to adsorb gaseous organic pollutants. This study explores the synergistic effects between the selection of central metals (e.g., titanium, iron, and aluminum) and the incorporation of –NH2 groups in terms of adsorption efficiency against gaseous formaldehyde (FA). A group of the pristine MIL MOFs is synthesized using three different metals (i.e., titanium, iron, and aluminum) and terephthalic acid along with their NH2 derivatives using 2-aminoterephthalic acid. Among the pristine forms, MIL-125(Ti) achieves the highest FA adsorption capacity (Q) of 26.96 mg g−1 and a partition coefficient (PC) of 0.0898 mol kg−1 Pa−1. Further, amination significantly improves the FA adsorption potential of NH2-MIL-125(Ti) with a Q value of 91.22 mg g−1 (PC = 0.3038 mol kg−1 Pa−1). In situ diffuse reflectance infrared Fourier-transform spectroscopy reveals that the FA adsorption of plain MILs should be governed primarily by physisorption. In contrast, FA adsorption of NH2-MILs appears to be regulated by both physisorption and chemisorption, while the latter being affected mainly through FA-NH2 interactions (Schiff base reactions). These findings provide valuable insights into the utility of aminated MIL sorbents, possibly toward the efficient management of indoor air quality.

Synthesis, Biological Activity Studies and Molecular Modeling Studies of Chalcone Compounds with Methyl Group

A series of new chalcone derivatives (1-5) were synthesized as a result of the Claisen-Schmidt condensation of different substituted methyl aldehydes of 4′-Piperazinoacetophenone. Anticholinesterase (AChE and BChE) inhibitory activity and antidiabetic (α-glucosidase and α-amylase inhibitory) activities of the synthesized compounds were examined. While compound 1 is the most active molecule in AChE (IC50= 16.29±0.44 μM), BChE (IC50 = 10.19±0.04 μM) and α-amylase (IC50= 105.51±0.24 μM) inhibitor activities; Compound 5 was found to be the most active molecule in α-glucosidase inhibitor activity. In silico and molecular docking studies of compounds 1-5 were performed. According to molecular docking results, all molecules were found to be more active than the reference compounds.

High-Throughput Screening Strategy for Electrocatalysts for Selective Catalytic Oxidation of Formaldehyde to Formic Acid.

Electrocatalytic oxidation of formaldehyde (FOR) is an effective way to prevent the damage caused by formaldehyde and produce high-value products. A screening strategy of a single-layer MnO2-supported transition metal catalyst for the selective oxidation of formaldehyde to formic acid was designed by high-throughput density functional calculation. N-MnO2@Cu and MnO2@Cu are predicted to be potential FOR electrocatalysts with potential-limiting steps (PDS) of 0.008 and -0.009 eV, respectively. Electronic structure analysis of single-atom catalysts (SACs) shows that single-layer MnO2 can regulate the spin density of loaded transition metal and thus regulate the adsorption of HCHO (Ead), and Ead is volcanically distributed with the magnetic moment descriptor -|mM - mH|. In addition, the formula quantifies Ead and |mM - mH| to construct a volcano-type descriptor α describing the PDS [ΔG(*CHO)]. Other electronic and structural properties of SACs and α are used as input features for the GBR method to construct machine learning models predicting the PDS (R2 = 0.97). This study hopes to provide some insights into FOR electrocatalysts.

A novel ratiometric formaldehyde fluorescent probe for applications in environmental, food, and biological systems

Formaldehyde (FA) is a toxic, irritating, colorless gas molecule widely used in food preservation, construction, paint, pharmaceutical and chemical industries. However, FA may enter the air, water and soil during its release, causing ecological damage and jeopardizing human health. Therefore, it is significant to seek a simple and effective assay for detecting FA in environment, food, and biological systems. Here, we designed and synthesized a novel phenothiazine-based fluorescent probe, JD-1, which exhibits ratiometric emission responses to FA at 400 nm and 505 nm. In addition, a solid sensor prepared by loading the probe JD-1 onto filter paper successfully achieved visual detection of liquid and gaseous FA. Notably, to further investigate the application scenarios of probe JD-1 in the detection of FA, we also prepared electrostatically spun fiber membranes by mixing probe JD-1 with PVDF-HFP, which were successfully used for the selective detection of FA. And the probe JD-1 possessed excellent stability in the detection of FA in real food samples, soil, live cells and zebrafish. Thus, this probe provides an attractive assay for the detection of FA in environment food, biological systems.

1,3-Dioxolane production via reactive distillation combined with vapor permeation: Experiments and modelling

To overcome the problem of difficult separation of the 1,3-dioxane (DOL)–H2O azeotrope in the production of DOL, a new process via reactive distillation (RD) combined with vapor permeation (VP) was established. The reliability of the RD model has been reported in the literature. The VP membrane used an Aspen Custom Modeler (ACM) self-built model, with the permeation parameters of H2O, DOL, and formaldehyde (FA) in the membrane flux equation fitted through the H2O-DOL-FA dehydration experiments by NaA zeolite membrane. The results showed that the relative error between the mass of H2O in a series of permeates in experiments and simulated by the VP model was mainly within 20%, and R2 is 0.94. For DOL and FA, which have very small permeation, the value was within 50%, implying the reliability of the VP model. On this basis, a two-dimensional VP model was established. Finally, a new RD-VP-D process for producing DOL was designed. The VP was used to overcome the azeotropic point of DOL and H2O by dehydration. Then 99.9 wt% DOL can be obtained at the bottom of the subsequent DOL purification column, with DOL- H2O azeotrope at the top recycled back to the VP membrane. The effects of the degree of VP dehydration and column pressure on membrane area, reboiler duty, and TAC were investigated, meanwhile introducing a new concept: logarithmic mean partial-pressure difference (LMPD). Under the optimal parameter, TAC was reduced by 20.0% compared with the process reported in the literature, and CO2 emissions were reduced by 35.8%.

Thermocatalytic oxidation potential of cobalt(II,III) oxide against gaseous formaldehyde in relation to hydrothermal synthesis temperature

The catalytic activity of various transition metal oxides has been reported to be tuned by controlling their synthesis conditions. In this perspective, the thermocatalytic oxidation performance of cobalt(II,III) oxides (Co3O4) against formaldehyde (FA) is studied in relation to the temperature selected for their hydrothermal synthesis (e.g., 30 (as room temperature (RT)), 60, 120, and 250℃) with the corresponding sample codes as Co3O4-RT, Co3O4-60, Co3O4-120, and Co3O4-250, respectively. The best performing Co3O4-RT records the lowest T90 (temperature required to obtain 90 % conversion) for 50 ppm FA at 72 °C when operated at 0 % relative humidity (RH), 30 mg (catalyst mass: mcat), and 100,000 mL g-1h−1 (weight hourly space velocity). The performance of Co3O4-RT, if assessed in terms of reaction kinetic rate (r) at XFA = 10 %, is 2.02E-02 mmol g-1h−1. According to X-ray photoelectron spectroscopy and temperature programmed characterization analysis, the catalytic activities of Co3O4-RT improve greatly through the synergistic combination of diverse factors (e.g., high Co3+ content, abundant oxygen vacancies (OVs) and surface adsorbed oxygen (Oβ) species, and good surface lattice oxygen (Oα) mobility). The analysis of in-situ diffuse reflectance infrared Fourier transform spectroscopy indicates that the FA should be oxidized into water (H2O) and carbon dioxide (CO2) via dioxymethylene (DOM) and formate (HCOO–) as reaction intermediates. The density functional theory simulations suggest the (111) surface of Co3O4 to be catalytically active against FA. The output of this research is expected to help establish effective strategies for designing high-performance transition metal oxide catalysts for the catalytic oxidation of FA.

Inactivation of an Indonesian isolate of foot-and-mouth disease virus using formaldehyde.

Foot-and-mouth disease (FMD) is a highly contagious viral disease that endangers livestock and the environment with significant economic consequences. This study aimed to validate the inactivation of the Indonesian isolate of foot-and-mouth disease virus (FMDV) with various formaldehyde concentration. The experiment started with FMDV being adapted on BHK-21 cells until cytopathic effects (CPE) appeared. The biological titer of the virus was determined using the 50% tissue culture infectious dose (TCID50) assay. The virus was inactivated by exposing the isolate to different formaldehyde (FA) concentrations (0.025%, 0.05%, 0.1%, and 0.2%) at 37°C for 24 h, and residual infectivity was assessed using CPE scoring of reinoculated BHK-21 cells. 72 h post-inoculation, the virulence of the FMDV isolate was indicated by complete CPE on BHK-21 monolayer cells, with a TCID50 value of 109/mL; CPE scoring did not signify significant differences (p < 0.05) among 0.025%, 0.05%, 0.1%, 0.2% FA, and the negative control. All treatment groups showed significant differences (p < 0.05) from the positive control (C+). FA concentrations inactivated the FMDV isolate under the given conditions. 0.025% and 0.05% FA continued to display CPE through the third passage, while 0.2% FA did not significantly differ from 0.1% FA (p > 0.05). 0.1% FA is the optimal concentration for safely and effectively inactivating FMDV. All of the formaldehyde concentrations can completely inactivate the FMDV isolate, with the most optimal and safe concentration being 0.1%.

Performance extrapolation of an ultraviolet-based photocatalytic air purifier against near-ambient-level formaldehyde

The practical utility of an air purifier (AP) with built-in adsorbent/catalyst-based filtration systems is assessed for the treatment of indoor volatile organic compounds (VOCs) through extrapolation of its performance based on a lab-scale chamber study. The feasibility of a commercial prototype AP unit with TiO2-based filters is tested in this work against 0.5–5 ppm formaldehyde (FA) in a 17 L chamber with an air recirculation rate of 565 h−1 under the control of key process variables (e.g., initial FA concentration, flow rate, and dark/light conditions). The performance of the AP unit is evaluated by the clean air delivery rate (CADR), quantum yield, and space time yield in diverse operation settings (e.g., photocatalysis only or along with adsorption). The effects of ultraviolet (UV) irradiation are evident as the CADR value of 5 ppm FA sharply increases from 5.67 (UV-off) to 15 L/min (UV-on): however, the CADR values increase only slightly (12 to 15 L/min) as the recirculation flow rate changes from 100 to 160 L/min, respectively. Further, FA concentration vs. time relationship exhibit an apparent bimodal exponential decay, with the fastest and near 100 % removal at [FA] < 0.5 ppm. The performance of the proposed AP platform in relatively large real-world volume (e.g., 4 m3, 2.4 h−1 air recirculation rate) is further estimated through extrapolation to offer valuable guidelines for the construction of AP systems in real-world applications.

Formaldehyde exacerbates inflammation and biases T helper cell lineage commitment through IFN-γ/STAT1/T-bet pathway in asthma

The correlation between formaldehyde (FA) exposure and prevalence of asthma has been widely reported. However, the underlying mechanism is still not fully understood. FA exposure at 2.0 mg/m3 was found to exacerbate asthma in OVA-induced murine models. IFN-γ, the cytokine produced by T helper 1 (Th1) cells, was significantly induced by FA in serum and bronchoalveolar lavage fluid (BALF) of asthmatic mice, which was different from cytokines secreted by other Th cells. The observation was also confirmed by mRNA levels of Th marker genes in CD4+ T cells isolated from BALF. In addition, increased production of IFN-γ and expression of T-bet in Jurkat T cells primed with phorbol ester and phytohaemagglutinin were also observed with 100 μM FA treatment in vitro. Upregulated STAT1 phosphorylation, T-bet expression and IFN-γ production induced by FA was found to be restrained by STAT1 inhibitor fludarabine, indicating that FA promoted Th1 commitment through the autocrine IFN-γ/STAT1/T-bet pathway in asthma. This work not only revealed that FA could bias Th lineage commitment to exacerbate allergic asthma, but also identified the signaling mechanism of FA-induced Th1 differentiation, which may be utilized as the target for development of interfering strategies against FA-induced immune disorders.

Isolation of Novel 6-methylideneoxecane-3,4,5,7,8,9-hexol from the Leaves of Rauwolfia vomitoria, Apocynaceae

Rauwolfia vomitoria (Wennberg) belongs to the family Apocynaceae, the dried leaves were extracted successively using n-hexane, dichloromethane, and 70% methanol, concentrated in vacuo. Extracts were subjected to antibacterial assay and the butanol fraction was subjected to chromatographic purification to obtain NBF12 which was subjected to spectral analysis. The antibacterial of n-Hexane, dichloromethane, and 70% methanol extracts was inactive against the screened organisms assessed (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa). NBF12 is yellowish crystals (10.5 mg), Rf (0.69), UV, max Abs (248) The carbon 13C-NMR spectrum displayed ten carbon atoms; one methylene, two methylene oxide carbon, 6-carbinolic carbon (Sp3) and a quaternary carbon (SP2). The spectrum showed a tertiary carbon at δ131.09 ppm, due to C-6 and at δ 114.74 ppm due to exocyclic methylidene carbon (Sp2) (C=CH2) linked to the C-6position. Based on the spectral data NBF12 is 6-methylideneoxecane-3,4,5,7,8,9-hexol with a molecular formula C10H18O7, molecular weight 250 g/mol.

Low-temperature thermocatalytic removal of formaldehyde in air using copper manganite spinels

The removal of formaldehyde (FA) is vital for indoor air quality management in light of its carcinogenic propensity and adverse environmental impact. A series of copper manganite spinel structures (e.g., CuMn2O4) are prepared using the sol-gel combustion method and treated with reduction or oxidation pretreatment at 300 °C condition. Accordingly, CuMn2O4–O (“O” suffix for oxidation pre-treatment in air) is identified as the best performer to achieve 100% conversion (XFA) of FA (50 ppm) at 90 °C; its performance, if assessed in terms of reaction kinetic rate (r) at XFA = 10%, is 5.02E-03 mmol g−1 h−1. The FA removal performance increases systematically with decreases in flow rate, FA concentration, and relative humidity (RH) or with increases in bed mass. The reaction pathways and intermediates of FA catalytic oxidation on CuMn2O4-A are studied with density functional theory simulations, temperature-programmed characterization experiments, and in-situ diffuse reflectance infrared Fourier transform spectroscopy. The synergistic combination of large quantities of adsorbed oxygen (OA) species and oxidized metal species (e.g., Cu2+) contribute to the enhanced catalytic performance of CuMn2O4–O to oxidize FA into CO2 with the reaction intermediates of H2CO2 (DOM), HCOO−, and CO. The present study is expected to provide valuable insights into the thermocatalytic oxidation of FA over spinel CuMn2O4 materials and their catalytic performances in relation to the key process variables.

An activatable formaldehyde donor with high contrast bioluminescence to monitor its release

High signal-to-background ratio (SBR) monitoring of formaldehyde (FA) delivery in living systems is of great significance for the precise study of the physiological and pathological functions of FA. However, traditional FA donors mainly use fluorescent signals to monitor FA release, which hampers the high-performance bioimaging due to the undesirable background autofluorescence, leading to poor SBR and compromised imaging sensitivity. Herein, we present the first bioluminogenic donor B-FAD for esterase-activated FA release with high contrast bioluminescence imaging. By protecting the hydroxyl group of D-luciferin with acetoxymethyl ether group, B-FAD cannot be catalyzed by luciferase to emit light. In the presence of esterase, the ester bond of B-FAD breaks, producing FA and D-luciferin. B-FAD selectively and sensitively releases FA in the presence of esterase, accompanied by 34-fold bioluminescence enhancement. In addition, B-FAD has been successfully applied for FA delivery and bioluminescence imaging in living cells, with a SBR about 50 times higher than those obtained by fluorescence imaging. Therefore, in addition to providing an effective tool for imaging FA delivery in living cells, this work establishes a general approach for high contrast monitoring other reactive biological species release by easily changing the responsive unit on D-luciferin.