One-to-Nine Single Spectroscopic Intelligent Probe for Risk Assessment of Multiple Metals in Drinking Water.

26% of the world's population lacks access to clean drinking water; clean water and sanitation are major global challenges highlighted by the UN Sustainable Development Goals, indicating water security in public water systems is at stake today. Water monitoring using precise instruments by skilled operators is one of the most promising solutions. Despite decades of research, the professionalism-convenience trade-off when monitoring ubiquitous metal ions remains the major challenge for public water safety. Thus, to overcome these disadvantages, an easy-to-use and highly sensitive visual method is desirable. Herein, an innovative strategy for one-to-nine metal detection is proposed, in which a novel thiourea spectroscopic probe with high 9-metal affinity is synthesized, acting as "one", and is detected based on the 9 metal-thiourea complexes within portable spectrometers in the public water field; this is accomplished by nonspecialized personnel as is also required. During the processing of multimetal analysis, issues arise due to signal overlap and reproducibility problems, leading to constrained sensitivity. In this innovative endeavor, machine learning (ML) algorithms were employed to extract key features from the composite spectral signature, addressing multipeak overlap, and completing the detection within 30-300 s, thus achieving a detection limit of 0.01 mg/L and meeting established conventional water quality standards. This method provides a convenient approach for public drinking water safety testing.

Few-Shot Learning-Based, Long-Term Stable, Sensitive Chemosensor for On-Site Colorimetric Detection of Cr(VI).

The rapid emergence of deep learning, e.g., deep convolutional neural networks (DCNNs) as one-click image analysis with super-resolution, has already revolutionized colorimetric determination. But it is severely limited by its data-hungry nature, which is overcome by combining the generative adversarial network (GAN), i.e., few-shot learning (FSL). Using the same amount of real sample data, i.e., 414 and 447 samples as training and test sets, respectively, the accuracy could be increased from 51.26 to 85.00% because 13,500 antagonistic samples are created and used by GAN as the training set. Meanwhile, the generated image quality with GAN is better than that with the commonly used convolution self-encoder method. The simple and rapid on-site determination of Cr(VI) with 1,5-diphenylcarbazide (DPC)-based test paper is a favorite for environment monitoring but is limited by unstable DPC, poor sensitivity, and narrow linear range. The chromogenic agent of DPC is protected by the blending of polyacrylonitrile (PAN) and then loaded onto thin chromatographic silica gel (SG) as a Cr(VI) colorimetric sensor (DPC/PAN/SG); its stability could be prolonged from 18 h to more than 30 days, and its repeatable reproducibility is realized via facile electrospinning. By replacing the traditional Ed method with DCNN, the detection limit is greatly improved from 1.571 mg/L to 50.00 µg/L, and the detection range is prolonged from 1.571-8.000 to 0.0500-20.00 mg/L. The complete test time is shortened to 3 min. Even without time-consuming and easily stained enrichment processing, its detection limit of Cr(VI) in the drinking water can meet on-site detection requirements by USEPA, WHO, and China.

Photodegradation Kinetics and Deep Learning-Based Intelligent Colorimetric Method for Bioavailability-Based Dissolved Iron Speciation.

Via the photodegradation of dissolved iron (dFe) complexes in the euphotic zone, released free Fe(III) is the most important source of bioavailable iron for eukaryotic phytoplankton. There is an urgent need to establish bioavailability-based dissolved iron speciation (BDIS) methods. Herein, an intelligent system with dFe pretreatment and a colorimetric sensor is developed for real-time monitoring of newly generated Fe(III) ions. According to the photodegradation kinetics of dFe, including kinetic constant and photogenerated time of free Fe(III) ions, 3 sources, 6 kinds, and 12 species of dFe are determined by our photocatalytic-assisted colorimetric sensor and deep learning model within 20.0 min. The algal dFe-uptake for 4 days can be predicted by BDIS with correlation coefficient 0.85, which could be explained by the hard and soft acids and bases theory (HSAB) and density functional theory (DFT). These results successfully demonstrate the proof-of-concept for photodegradation kinetics-based speciation and bioavailability assessments of dissolved metals.

Responses of nickel bioavailability and toxicity of Prorocentrum Donghaienses to dissolved organic matter (DOM) fractions incubated in urea.

Urea, nickel (Ni) and dissolved organic matter (DOM) from land varied with different sources have a great impact on the offshore ecosystem. The heterogeneity of Ni bioavailability and toxicity of Prorocentrum donghaiense influenced by DOM fractions incubated in urea was investigated in this study. On the occasion, chlorophyll (Chl a) concentration, growth rate, and photosynthesis parameters were monitored to track changes occurring in the test organism. Chl a concentration and photosynthesis parameters in the treatment of hydrophilic DOM (HPI) with Ni-free was significantly higher than that in the control treatment, and similar data were shown in the treatment of hydrophobic DOM（HPO）with the low Ni environment (0.17µmol L-1). However, the opposite phenomena were observed in the treatments of HPO with the higher Ni environment (over 170µmol L-1). Moreover, the EC50 of Ni for P.donghaiense incubated in HPO was relatively lower than that in HPI and control treatment, which implied that HPO elevated the toxicity of Ni. Therefore, the varied DOM compositions because of different origins, as a chelating agent and potential nutrient source in coastal waters, shows the significantly different bioavailability and toxicity of Ni with the increasing inputs of urea, which in turn influences the dynamics of phytoplankton.

[Anti-arthritic-related metal bioavailability for optimal compatibility ratio of Aconiti Radix Cocta and Paeoniae Radix Alba].

Trace metals deficiency or excess are associated with the etiology and pathogenesis of rheumatoid arthritis(RA). Aconiti Radix Cocta(A) and Paeoniae Radix Alba(B) are commonly used together for the treatment of RA. In this study, we aim to determine anti-arthritic-related metal bioavailability in the compatibility of herb A and B for avoiding metal deficiency or excess, and optimize the combination ratio of herb A and B, accordingly. Anti-arthritic-related metal bioaccessibility were evaluated by in vitro simulator of all gastrointestinal tract(including mouth, stomach, small and large intestines), and the roles of gastrointestinal digestive enzymes and intestinal microflora were investigated. Anti-arthritic-related metal bioavailability was assessed by the affinity adsorption with liposomes. The results indicated that compatibility proportion of corresponding herbal plants, gastrointestinal digestion and microbial metabolic, which could affect metal digestion and absorption. The optimal compatibility proportion of 1 A∶1 B is recommended, according to the dose of anti-arthritic-related metal bioavailability, which is often chosen for clinical practice of RA therapy. Thus, anti-arthritic-related metal bioavailability might be the key active substances for RA treatment.

Simultaneous determination of dopamine and uric acid in the presence of ascorbic acid using a gold electrode modified with carboxylated graphene and silver nanocube functionalized polydopamine nanospheres.

A voltammetric sensor is presented for the simultaneous determination of dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA). It is based on a gold electrode (GE) modified with carboxyl-functionalized graphene (CFG) and silver nanocube functionalized DA nanospheres (AgNC@PDA-NS). The AgNC@PDA-NS nanocomposite was characterized by scanning electron microscopy and UV-Vis spectroscopy. The electrochemical behavior of the modified electrode was evaluated by electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. The modified electrode displays good electrocatalytic activity towards DA (typically at 0.14 V vs. Ag/AgCl) and UA (typically at 0.29 V vs. Ag/AgCl) even in the presence of ascorbic acid. Response to DA is linear in the concentration range of 2.5 to 130 µM with a detection limit of 0.25 µM. Response to UA is linear in the concentration range of 10 to 130 µM with a detection limit of 1.9 µM. In addition, the sensitivity for DA and UA is 0.538 and 0.156 µA µM-1 cm-2, respectively. The modified electrode also displays good stability, selectivity and reproducibility. Graphical abstract The gold electrode modified with polydopamine nanospheres functionalized with silver nanocube and carboxylated graphene is used for simultaneous determination of DA and UA in the presence of AA, with wide linear range and low detection limit.

Highly crystalline graphitic carbon nitride quantum dots as a fluorescent probe for detection of Fe(III) via an innner filter effect.

Bulk g-C3N4 was transformed into water-soluble graphitic carbon nitride quantum dots (g-CNQDs) via a chemical oxidation and liquid exfoliation process. The g-CNQDs possess a size distribution ranging from 1 to 5 nm (centered at 3 nm), excellent crystallinity, and are water soluble. It is found that Fe(III) ions are adsorbed on the surface of the g-CNQDs via electrostatic interaction, and that the blue fluorescence of the g-CNQDs is reduced by Fe(III) via an inner filter effect. By using the g-CNQDs as a fluorescent probe, Fe(III) can be determined at excitation/emission wavelengths of 241/368 nm in spiked natural water samples within 1 min and with good selectivity over other ions. Response is linear in the 0.2-60 µmol·L-1 Fe(III) concentration range, and the detection limit is 23 nmol·L-1. Graphical abstract Graphitic carbon nitride quantum dots (g-CNQDs) emit blue fluorescence at an excitation wavelength of 241 nm. Fe(III) ions are quickly adsorbed on the g-CNQDs via electrostatic interaction, and fluorescence is quenched due to an inner filter effect.

Monodisperse hollow spheres with sandwich heterostructured shells as high-performance catalysts via an extended SiO2 template method.

To improve and extend the SiO2 template method for preparing metal oxide hollow spheres, a general and facile "sol-gel and hydrothermal" method is developed to replace the current "sol-gel, calcination, and base-etching" processes for the construction of well-defined sandwich metal oxide@noble metal NP@metal oxide hollow spheres. As-synthesized hollow spheres exhibit high performances in various catalytic reactions.

Constituting fully integrated visual analysis system for Cu(II) on TiO2/cellulose paper.

As a cheap and abundant porous material, cellulose filter paper was used to immobilize nano-TiO2 and denoted as TiO2/cellulose paper (TCP). With high adsorption capacity for Cu(II) (more than 1.65 mg), TCP was used as an adsorbent, photocatalyst, and colorimetric sensor at the same time. Under the optimum adsorption conditions, i.e., pH 6.5 and 25 °C, the adsorption ratio of Cu(II) was higher than 96.1%. Humic substances from the matrix could be enriched onto TCP but the interference of their colors on colorimetric detection could be eliminated by the photodegradation. In the presence of hydroxylamine, neocuproine, as a selective indicator, was added onto TCP, and a visual color change from white to orange was generated. The concentration of Cu(II) was quantified by the color intensity images using image processing software. This fully integrated visual analysis system was successfully applied for the detection of Cu(II) in 10.0 L of drinking water and seawater with a preconcentration factor of 10(4). The log-linear calibration curve for Cu(II) was in the range of 0.5-50.0 µg L(-1) with a determination coefficient (R(2)) of 0.985 and its detection limit was 0.073 µg L(-1).

[Application of in vitro bionic digestion and biomembrane extraction for metal speciation analysis, bioavailability and risk assessment in lianhua qingwen capsule].

One of the causes of the high cost of pharmaceuticals and the major obstacles to rapidly assessing the bioavailability and risk of a chemical is the lack of experimental model systems. A new pre-treatment technology, in vitro bionic digestion was designed for metal analysis in Lianhua Qingwen capsule. The capsule was digested on 37 degrees C under the acidity of the stomach or intestine, and with the inorganic and organic compounds (including digestive enzymes) found in the stomach or intestine, and then the chyme was obtained. Being similar to the biomembrane between the gastrointestinal tract and blood vessels, monolayer liposome was used as biomembrane model Affinity-monolayer liposome metals (AMLMs) and water-soluble metals were used for metal speciation analysis in the capsule. Based on the concentration of AMLMs, the main absorption site of trace metals was proposed. The metal total contents or the concentration of AMLMs in the capsule were compared to the nutritional requirements, daily permissible dose and heavy metal total contents from the "import and export of medicinal plants and preparation of green industry state standards". The metal concentrations in the capsule were within the safety baseline levels for human consumption. After in vitro bionic digestion, most of trace metals were absorbed mainly in intestine. The concentration of As, Cd, Pb was 0.38, 0.07, 1.60 mg x kg(-1), respectively, far less than the permissible dose from the "import and export of medicinal plants and preparation of green industry state standards".

No-interfered and visual evaluation of global warming impacts on phytoplankton-based copper bioavailability and then carbon sequestration.

Global warming has an increasingly serious impact on the ecological environment. Copper bioavailability plays an important physiological role in revealing the mechanism of carbon cycle, photosynthesis, and respiration. Here we reported a multifunctional carbon quantum dots fluorescence probe for no-interfered and visual determination of phytoplankton-based intracellular Cu(II), glucose, and reactive oxygen species (ROS). Glucose and ROS were explored to reflect the change in primary biomass and carbon sequestration. H2O2 is acted as the standard material of ROS, and the fitting parameter for glucose and H2O2 concentrations was 0.42(r = 0.9972). Both glucose, ROS, and Cu2+ detection have advantages of wide linear range (24.8-3.96 × 105 µg/L, 6-9.6 × 105 ng/L and 5-15 × 103 nmol/L, respectively), high precision (1.22 %, 6.38 %, and 7.37 %, respectively), and low detection limit (86.7 ng/L, 5.32 ng/L, and 0.367 nmol/L, respectively). Cu2+ uptake was increased with the increasing of temperature, and the copper bioavailability in increasing order was Cu-PorPhyr > Cu-phthalate > Cu-EDTA. There were significant positive correlation between glucose and Cu2+(r = 0.9943). Copper bioavailability would directly affect the carbon sequestration, i.e., when the concentration of intracellular copper increases by 1 mg/L, the content of intracellular glucose increases by 412 mg/L approximately, equally to 2.47 g/L of carbon dioxide was fixed.

Carbon sequestration reduced by the interference of nanoplastics on copper bioavailability.

Microplastics (MPs) have been recognized as a serious new pollutant, especially nanoplastics (NPs) pose a greater threat to marine ecosystem than larger MPs. Within these ecosystems, phytoplankton serve as the foundational primary producers, playing a critical role in carbon sequestration. Copper (Cu), a vital cofactor for both photosynthesis and respiration in phytoplankton, directly influences their capacity to regulate atmospheric carbon. Therefore, we assessed the impact of NPs on Cu bioavailability and carbon sequestration capacity. The results showed that polystyrene nanoplastics (PS-NPs) could inhibit the growth of Thalassiosira weissflogii (a commonly used model marine diatom) and Chlorella pyrenoidosa (a standard strain of green algae). The concentration of Cu uptake by algae has a significant negative correlation with COPT1 (a Cu uptake protein), but positive with P-ATPase (a Cu efflux protein). Interestingly, PS-NPs exposure could reduce Cu uptake and carbon Cu sequestration capacity of algae, i.e., when the concentration of PS-NPs increases by 1 mg/L, the concentration of fixed carbon dioxide decreases by 0.0023 ppm. This provides a new perspective to reveal the influence mechanisms of PS-NPs on the relationship between Cu biogeochemical cycling and carbon source and sink.

Molecular recognition and quantitative analysis of xylene isomers utilizing cataluminescence sensor array.

A facile and effective sensor array consisting of three cataluminescence (CTL) sensors based on nanomaterial Y(2)O(3), γ-Al(2)O(3) and ZrO(2) as probes was firstly proposed for the molecular recognition and quantitative analysis of xylene isomers. Under the optimized conditions, the linear range of CTL intensity versus concentration of xylene isomers was 86.70-8670.00 mg m(-3). The use of a sensor array instead of a single sensor has provided a novel strategy for the process of identifying similar chemical compounds, which should have a bright future in environmental and industrial monitoring.

[Application of bionic technology to speciation analysis and bioavailability assessment of nickel in transgenic soybean].

The safety of transgenic food has been paid the most attention to by the public and scientists. Trace metal bioavailability could provide information for safety assessment of transgenic food. The critical functional digestion and absorption in the gastrointestinal tract were simulated by bionic gastrointestinal digestion, metabolism of gut microbiota, and bionic biomembrane adsorption with liposome and then used for the pretreatment of transgenic and general soybeans. Ni speciation in the chyme was defined as affinity-liposome and water soluble Ni. Nickel bioavailability was assessed by the content of affinity-liposome Ni. Water soluble Ni was the main species of nickel complex in the chyme. Nickel bioavailability was 4.1% for transgenic soybean and 3.3% for general soybean, which could be enhanced by gastrointestinal digestion and metabolism of gut microbiota. After transgene, nickel bioavailability was increased 24% but the content of affinity-liposome Ni was 122.3 ng x g(-1) for transgenic soybean, just as 36% as that of general soybean.

Effects of phosphorus species and zinc stress on growth and physiology of the marine diatom Thalassiosira weissflogii.

Human activities, including industrial and agricultural production, as well as domestic sewage discharge, have led to heavy metal pollution and eutrophication in coastal waters. This has caused a deficiency of dissolved inorganic phosphorus (DIP), but an excess dissolved organic phosphorus (DOP) and high concentrations of zinc. However, the impact of high zinc stress and different phosphorus species on primary producers remains unclear. This study examined the impact of different phosphorus species (DIP and DOP) and high zinc stress (1.74 mg L-1) on the growth and physiology of the marine diatom Thalassiosira weissflogii. The results showed that compared to the low zinc treatment (5 µg L-1), high zinc stress significantly decreased the net growth of T. weissflogii, but the decline was weaker in the DOP group than in the DIP group. Based on changes in photosynthetic parameters and nutrient concentrations, the study suggests that the growth inhibition of T. weissflogii under high zinc stress was likely due to an increase in cell death caused by zinc toxicity, rather than a decrease in cell growth caused by photosynthesis damage. Nonetheless, T. weissflogii was able to reduce zinc toxicity by antioxidant reactions through enhancing activities of superoxide dismutase and catalase and by cationic complexation through enhancing extracellular polymeric substances, particularly when DOP served as the phosphorus source. Furthermore, DOP had a unique detoxification mechanism by producing marine humic acid, which is conducive to complexing metal cations. These results provide valuable insights into the response of phytoplankton to environmental changes in coastal oceans, particularly the effects of high zinc stress and different phosphorus species on primary producers.

The interference of marine accidental and persistent petroleum hydrocarbons pollution on primary biomass and trace elements sink.

More than 80 % of the primary biomass in marine environments is provided by phytoplankton. The primary mechanism in the trace element sink is the absorption of trace elements by phytoplankton. Because of their difficult degradability and bioaccumulation, petroleum hydrocarbons are one of the most significant and priority organic contaminants in the marine environment. This study chose Chlorella pyrenoidosa as the model alga to be exposed to short and medium-term petroleum hydrocarbons. The ecological risk of accidental and persistent petroleum hydrocarbon contamination was thoroughly assessed. The interaction and intergenerational transmission of phytoplankton physiological markers and trace element absorption were explored to reflect the change in primary biomass and trace element sink. C. pyrenoidosa could produce a large number of reactive oxygen species stimulated by the concentration and exposure time of pollutants, which activated their antioxidant activity (superoxide dismutase (SOD) activity, ß-carotene synthesis, antioxidant trace elements uptake) and peroxides production (hydroxyl radicals and malondialdehyde). The influence of the growth phase on SOD activity, copper absorption, and manganese adsorption in both persistent and accidental pollution was significant (p < 0.05, F > Fα). Adsorption of manganese and selenium positively connected with SOD, malondialdehyde, and Chlorophyl-a (p < 0.01). These findings convincingly indicate that petroleum hydrocarbon contamination can interfere with primary biomass and trace element sinks.

A dual-confinement strategy to construct cobalt-based phosphide nanoclusters within carbon nanofibers for bifunctional water splitting electrocatalysts.

It is a challenging task to explore highly active and stable noble-metal-free bifunctional electrocatalysts for water splitting, both in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, a new dual-confinement strategy for the fabrication of cobalt-base phosphide in the carbon nanofibers (CNFs) was proposed via electrospinning, followed by the corresponding pyrolysis. The ultrafine phosphides derived from the pore confinement of ZIF and space confinement of the polymer revealed abundant active sites and P defects. More importantly, by introducing a second metal element Ni or Cu, the electronic structure and synergistic effect were further enhanced, and the obtained bimetallic CoNiPx-CNF electrocatalyst exhibited the remarkable performance for HER and OER, featuring the low η10 values of 154 and 269 mV in 1.0 M KOH electrolyte, respectively. CoNiPx-CNFs as a catalyst for both anode and cathode showed a current density of 10 mA cm-2 at a voltage of 1.56 V, exceeding better stability, which is superior to most non-noble metal electrocatalysts reported in a previous research. The dual-confinement strategy is believed to provide an effective and simple approach for the synthesis of high-performance and cost-efficient bifunctional electrocatalysts for overall water splitting.

Nitrogen-doped carbon@TiO2 double-shelled hollow spheres as an electrochemical sensor for simultaneous determination of dopamine and paracetamol in human serum and saliva.

As the most commonly used antipyretic and analgesic drug, paracetamol (PA) coexists with neurotransmitter dopamine (DA) in real biological samples. Their simultaneous determination is extremely important for human health, but they also interfere with each other. In order to improve the conductivity, adsorption affinity, sensitivity, and selectivity of TiO2-based electrochemical sensor, N-doped carbon@TiO2 double-shelled hollow sphere (H-C/N@TiO2) is designed and synthesized by simple alcoholic and hydrothermal method, using polystyrene sphere (PS) as a template. Meanwhile, TiO2 hollow spheres (H-TiO2) or N-doped carbon hollow spheres (H-C/N) are also prepared by the same method. H-C/N@TiO2 has good conductivity, charge separation, and the highly enhanced and stable current responses for the detection of PA and DA. The detection limit and linear range are 50.0 nmol/L and 0.3-50 µmol/L for PA, 40.0 nmol/L and 0.3-50 µmol/L for DA, respectively, which are better than those of carbon-based sensors. Moreover, this electrochemical sensor, with high selectivity, strong anti-interference, high reliability, and long time durability, can be used for the simultaneous detection of PA and DA in human blood serum and saliva. The high electrochemical performance of H-C/N@TiO2 is attributed to the multi-functional combination of different layers, because of good conductivity, absorption and electrons transfer ability from in-situ N-doped carbon and electrocatalytic activity from TiO2.

Preparation of carbonyl, hydroxyl, and amino-functionalized microporous carbonaceous nanospheres from syrup-based waste to remove sulfamethazine.

Sulfadiazine (SDZ) was a persistent sulfonamide antibiotic with a potential risk to human health. The waste dipping syrup was considered useless and environmentally unfriendly solution. In this work, carbonyl-, hydroxyl-, and amino-functionalized microporous carbonaceous nanospheres were synthesized using waste dipping syrup with glucose, fructose, and nitrogen, which was used as precursor for hydrothermal and pyrolysis process. The products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), the point of zero charge (PZC), Xray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The carbonaceous nanospheres with large BET surface area (924.528 m2/g), micropores (2.127 nm), and high micro-porosity (89.54 %) allowed the rapid diffusion of SDZ (0.512nm×0.738 nm) into micropores of nanospheres. The majority SDZ (initial concentration = 20 mg/L) was removed (>96.8%) in the presence of 1.0 g/L nanoparticles after 40-min reaction at pH = 6.0. The adsorption capacity of SDZ onto nanospheres was 96.6 mg/g. The adsorption kinetic and equilibrium followed pseudo-first-order model and Langmuir isotherm, respectively. The intra-particle diffusion model indicated a three-step adsorption process. In addition, the regenerated nanospheres could be reused over four recycles. The optimal fabrication was realized at lower hydrothermal and pyrolysis temperature of 180 °C and 400 °C, respectively, which involved no additional chemical activating agent and had a high yield (70.8 %). Collectively, hydroxylation, carboxylation, amination, large specific surface area, and multi-microporosity may be responsible for improved adsorption performance of SDZ onto nanospheres. The findings provided a novel pathway for SDZ-loading wastewater treatment using waste syrup.

Thalassiosira weissflogii grown in various Zn levels shows different ecophysiological responses to seawater acidification.

The presence of zinc (Zn), a vital element for algal physiological functions, coupled with the silicification of diatoms implies that it plays an integral role in the carbon and silicon cycles of the sea. In this study, we examined the effects of different pCO2 and Zn levels on growth rate, elemental compositions and silicification by Thalassiosira weissflogii. The results showed that under normal pCO2 (400 µatm), cultures of T. weissflogii were depressed for growth rate and silica incorporation rate, but encouraged for cellular silicon content, Si/C, Si/N, and sinking rate when Zn deficient (0.3 pmol L-1). However, cellular silicon and sinking rate of Zn-deficient and Zn-replete (25 pmol L-1) T. weissflogii were decreased and increased at higher pCO2 (800 µatm), respectively. Thus, acidification may affect diatoms significantly differently depending on the Zn levels of the ocean and then alter the biochemical cycling of carbon and silica.