DNA Nanoflowers Research Articles

Preparation of DNA nanoflower-modified capillary silica monoliths for chiral separation.

Innovative chiral capillary silica monoliths (CSMs) were developed based on DNA nanoflowers (DNFs). Baseline separation of enantiomers such as atenolol, tyrosine, histidine, and nefopam was achieved by using DNF-modified CSMs, and the obtained resolution value was higher than 1.78. To further explore the effect of DNFs on enantioseparation, different types of chiral columns including DNA strand containing the complementary sequence of the template (DCT)-modified CSMs, DNF2-modified CSMs, and DNF3-modified CSMs were prepared as well. It was observed that DNF-modified CSMs displayed better chiral separation ability compared with DCT-based columns. The intra-day and inter-day repeatability of model analytes' retention time and resolution kept desirable relative standard deviation values of less than 8.28%. DNF2/DNF3-modified CSMs were able to achieve baseline separation of atenolol, propranolol, 2'-deoxyadenosine, and nefopam enantiomers. Molecular docking simulations were performed to investigate enantioselectivity mechanisms of DNA sequences for enantiomers. To indicate the successful construction of DNFs and DNF-modified CSMs, various charaterization approaches including scanning electron microscopy, agarose gel electrophoresis, dynamic light scattering analysis, electroosmotic flow, and Fourier-transform infrared spectroscopy were utilized. Moreover, the enantioseparation performance of DNF-modified CSMs was characterized in terms of sample volume, applied voltage, and buffer concentration. This work paves the way to applying DNF-based capillary electrochromatography microsystems for chiral separation.

Aptamer-Loop DNA Nanoflower Recognition and Multicolor Fluorescent Carbon Quantum Dots Labeling System for Multitarget Living Cell Imaging.

Visualization of multiple targets in living cells is important for understanding complex biological processes, but it still faces difficulties, such as complex operation, difficulty in multiplexing, and expensive equipment. Here, we developed a nanoplatform integrating a nucleic acid aptamer and DNA nanotechnology for living cell imaging. Aptamer-based recognition probes (RPs) were synthesized through rolling circle amplification, which were further self-assembled into DNA nanoflowers encapsulated by an aptamer loop. The signal probes (SPs) were obtained by conjugation of multicolor emission carbon quantum dots with oligonucleotides complementary to RPs. Through base pairing, RPs and SPs were hybridized to generate aptamer sgc8-, AS1411-, and Apt-based imaging systems. They were used for individual/simultaneous imaging of cellular membrane protein PTK7, nucleolin, and adenosine triphosphate (ATP) molecules. Fluorescence imaging and intensity analysis showed that the living cell imaging system can not only specifically recognize and efficiently bind their respective targets but also provide a 5-10-fold signal amplification. Cell-cycle-dependent distribution of nucleolin and concentration-dependent fluorescence intensity of ATP demonstrated the utility of the system for tracking changes in cellular status. Overall, this system shows the potential to be a simple, low-cost, highly selective, and sensitive living cell imaging platform.

Potential-Resolved Ratio Electrochemiluminescence Biosensor Based on Perylene Diimide-MOF and DNA Nanoflowers-CdS Quantum Dots for Detection of Dual Targets.

BRCA1 gene and carcinoembryonic antigen (CEA) are important markers of breast cancer, so accurate detection of them is significant for early detection and diagnosis of breast cancer. In this study, a potential-resolved ratio electrochemiluminescence (ECL) biosensor using perylene diimide (PDI)-metal-organic framework and DNA nanoflowers (NFs)-CdS quantum dots (QDs) was constructed for detection of BRCA1 and CEA. Specifically, PDI-MOF and CdS QDs can generate potential-resolved intense ECL signals only using one coreactant, so the detection procedure can be effectively simplified. PDI-MOF was first attached to the electrode by graphene oxide, and the dopamine (DA) probe was linked to quench the ECL signal by DNA hybridization. In the presence of target BRCA1, it can form a bipedal DNA walker, so the quenching molecules (DA) were detached from the electrode via the walker amplification process aided by Mg2+, so that the PDI signal at -0.25 V was restored for the BRCA1 assay. Moreover, CdS QDs@DNA NFs as amplified signal probes were formed by self-assembly, and the target CEA-amplified product introduced the CdS QDs@DNA NFs to the electrode, so the QD ECL signal at -1.42 V was enhanced, while the ECL signal of PDI is unchanged; thus, CEA detection was achieved by the ratio value between them. Therefore, the detection accuracy is guaranteed by detection of two cancer markers and a ratio value. This biosensor has a great contribution to the development of new ECL materials and a novel ECL technique for fast and efficient multitarget assays, showing great significance for the early monitoring and diagnosis of breast cancer.

Multifunctional DNA Nanoflower Applied for High Specific Photodynamic Cancer Therapy In Vivo.

Photodynamic therapy (PDT) is a newly emerged strategy for disease treatment. One challenge of the application of PDT drugs is the side-effect caused by the non-specificity of the photosensitive molecules. Most of the photosensitizers may invade not only the pathogenic cells but also the normal cells. In recent, people tried to use special cargoes to deliver the drugs into target cells. DNA nanoflowers (NFs) are a kind of newly-emerged nanomaterial which constructed through DNA rolling cycle amplification (RCA) reaction. It is reported that the DNA NFs were suitable materials which have been widely applied as nanocargos for drug delivery in cancer chemotherapeutic treatment. In this paper, we have introduced a new multifunctional DNA NF which could be prepared through an one-pot RCA reaction. This proposed DNA NF contained a versatile AS1411 G-quadruplex moiety, which plays key roles not only for specific recognition of cancer cells but also for near-infrared ray based photodynamic therapy when conjugating with a special porphyrin molecule. We demonstrated that the DNA NF showed good selectivity toward cancer cells, leading to highly efficient photo-induced cytotoxicity. Moreover, the in vivo experiment results suggested this DNA NF is a promising nanomaterial for clinical PDT.

Advancements in Aptamer-Driven DNA Nanostructures for Precision Drug Delivery.

DNA nanostructures exhibit versatile geometries and possess sophisticated capabilities not found in other nanomaterials. They serve as customizable nanoplatforms for orchestrating the spatial arrangement of molecular components, such as biomolecules, antibodies, or synthetic nanomaterials. This is achieved by incorporating oligonucleotides into the design of the nanostructure. In the realm of drug delivery to cancer cells, there is a growing interest in active targeting assays to enhance efficacy and selectivity. The active targeting approach involves a "key-lock" mechanism where the carrier, through its ligand, recognizes specific receptors on tumor cells, facilitating the release of drugs. Various DNA nanostructures, including DNA origami, Tetrahedral, nanoflower, cruciform, nanostar, nanocentipede, and nanococklebur, can traverse the lipid layer of the cell membrane, allowing cargo delivery to the nucleus. Aptamers, easily formed in vitro, are recognized for their targeted delivery capabilities due to their high selectivity for specific targets and low immunogenicity. This review provides a comprehensive overview of recent advancements in the formation and modification of aptamer-modified DNA nanostructures within drug delivery systems.

Nucleic Acid-Binding Dyes as Versatile Photocatalysts for Atom-Transfer Radical Polymerization.

Nucleic acid-binding dyes (NuABDs) are fluorogenic probes that light up after binding to nucleic acids. Taking advantage of their fluorogenicity, NuABDs have been widely utilized in the fields of nanotechnology and biotechnology for diagnostic and analytical applications. We demonstrate the potential of NuABDs together with an appropriate nucleic acid scaffold as an intriguing photocatalyst for precisely controlled atom-transfer radical polymerization (ATRP). Additionally, we systematically investigated the thermodynamic and electrochemical properties of the dyes, providing insights into the mechanism that drives the photopolymerization. The versatility of the NuABD-based platform was also demonstrated through successful polymerizations using several NuABDs in conjunction with diverse nucleic acid scaffolds, such as G-quadruplex DNA or DNA nanoflowers. This study not only extends the horizons of controlled photopolymerization but also broadens opportunities for nucleic acid-based materials and technologies, including nucleic acid-polymer biohybrids and stimuli-responsive ATRP platforms.

DNA nanoflowers encapsulating horseradish peroxidase as a signal amplification tag for rapid diagnosis in cytology specimens

Rapid analysis of cytology samples obtained by minimally invasive sampling is essential in clinical diagnosis, yet existing diagnostic methods are often cumbersome and time-consuming. To rapidly detect the scanty number of cells in specimens, a multifunctional detection probe based on DNA nanoflower structure was prepared in this study, which possesses both signal output capability of fluorescence and oxidation reaction (colorimetric assay) for ultra-sensitive cancer cell detection. Firstly, DNA nanoflowers encapsulating horseradish peroxidase (HRP-DNA Nanoflowers, HDFs) were prepared by the rolling circle amplification (RCA) reaction and then hybridized with the aptamers labeled with fluorophores to construct the multivalent aptamer HDFs (Multi-Aptamer-HDFs) with fluorescence effect and efficient cancer cell targeting. The Multi-Aptamer-HDFs probe can be used to detect fresh clinical cytology specimens directly for fluorescence observation with sensitivity and specificity of 88.64%, and 84.85%, respectively. In addition, Multi-Aptamer-HDFs has peroxidase activity due to the encapsulation of HRP, which can catalyze the oxidation of substrates such as ABTS and DAB for color development. Therefore, we applied Multi-Aptamer-HDFs to one-step staining of clinical cytology cell blocks with a sensitivity of 88.41% and a specificity of 83.33%, which required fewer steps and reagents with a significantly shorter time required for immunocytochemical staining. The multifunctional probe, Multi-Aptamer-HDFs, prepared in this study is expected to be better applied in the rapid cellular analyses and one-step immunostaining, which is expected to provide a new means for rapid on-site assessment and on-site preliminary diagnosis.

Oxygen-producing and pH-responsive targeted DNA nanoflowers for enhanced chemo-sonodynamic therapy of lung cancer

Lung cancer is the deadliest kind of cancer in the world, and the hypoxic tumor microenvironment can significantly lower the sensitivity of chemotherapeutic drugs and limit the efficacy of different therapeutic approaches. In order to overcome these problems, we have designed a drug-loaded targeted DNA nanoflowers encoding AS1411 aptamer and encapsulating chemotherapeutic drug doxorubicin and oxygen-producing drug horseradish peroxidase (DOX/HRP-DFs). These nanoflowers can release drugs in response to acidic tumor microenvironment and alleviate tumor tissue hypoxia, enhancing the therapeutic effects of chemotherapy synergistic with sonodynamic therapy. Owing to the encoded drug-loading sequence, the doxorubicin loading rate of DNA nanoflowers reached 73.24 ± 3.45%, and the drug could be released quickly by disintegrating in an acidic environment. Furthermore, the AS1411 aptamer endowed DNA nanoflowers with exceptional tumor targeting properties, which increased the concentration of chemotherapeutic drug doxorubicin in tumor cells. It is noteworthy that both in vitro and in vivo experiments demonstrated DNA nanoflowers could considerably improve the hypoxia of tumor cells, which enabled the generation of sufficient reactive oxygen species in combination with ultrasound, significantly enhancing the therapeutic effect of sonodynamic therapy and evidently inhibiting tumor growth and metastasis. Overall, this DNA nanoflowers delivery system offers a promising approach for treating lung cancer.

Overview of Advances in DNA Nanoflower Biomedical Research

Overview of Advances in DNA Nanoflower Biomedical Research

Self-assembled programmable DNA nanoflower for in situ synthesis of gold nanoclusters and integration with Mn-MOF to sensitively detect AFB1

Aflatoxin B1 (AFB1) is a potent carcinogenic mycotoxin that is susceptible to contamination of agricultural products and can cause chronic effects on humans. Thus, the establishment of highly sensitive and efficient AFB1 detection method is crucial to ensure food safety and human health. Here, we developed programmable DNA nanoflowers (DNF) with dual functionality for in situ synthesis of gold nanoclusters (AuNCs) and DNA recognition. The AuNCs synthesized using DNF as template (DNF@AuNCs) possessed good fluorescence properties and stability, and were applied as stable signal probes for constructing sensitive aptasensor. DNF completed the transition from bud to blooming flower, shifting its morphology from 3D to 2D structure during the in-situ synthesis of AuNCs, leading to the exposure of more template sequences. The designed hairpins DNA were subsequently used for local catalytic hairpin assembly (LCHA) on the surface of Mn-MOF. A substantial number of amplified products H2-H3 was obtained by conformational conversion, which was complementary to the sequence of DNF. Upon hybridization of H2-H3 with DNF@AuNCs, the fluorescence of AuNCs is quenched by adjacent guanine-rich (G-rich) base at the 3′ end of H3. The switch of LCHA is controlled by the conformational change of H1 which contains the AFB1 aptamer sequence, thus enabling precise detection of AFB1. The DNF@AuNCs and Mn-MOF-based fluorescence aptasensor achieved a detection limit of 7 pg/mL for AFB1, with a detection range of 0.01–200 ng/mL. The aptasensor also exhibits high selectivity, reproducibility, and stability, making it prospective for food safety monitoring.

Entropy-driven multicolor DNA nanoflowers for simultaneous and rapid detection of multiple heavy metal ions in water

Heavy metal ions (HMIs), including Pb2+, Cu2+, and Hg2+, has shown great threat to the environment and public health worldwide owing to their high toxic at trace levels. However, conventional laboratory-based methods for analyzing HMIs require expensive instrumentation and complex operations limit their further application. In this study, we present a novel “two-step” approach based on entropy-driven multicolor DNA nanoflowers (DNFL) for the simultaneous ultrasensitive detection of three typical HMIs (Pb2+, Cu2+, and Hg2+). Through specific cleavage/competition reactions initiated by the target metal ions, a large number of single-stranded DNA (ssDNA) are produced, triggering the blooming of DNFL. Subsequently, with the assistance of fuel strands, an entropy-driven strand displacement reaction (ESDR) will further accelerate the conformational change of DNFL within one hour. Different fluorophores (FAM, ROX, and Cy5) attached to the opened DNFL serve as indicator molecules for the respective HMIs. After reasonable design and optimization, the developed fluorescence analysis method demonstrates excellent analytical performance (with limit of detection, 0.13 nM, 3.5 pM, 4.6 pM for Pb2+, Cu2+, and Hg2+, respectively) and can be applied to the simultaneous and rapid detection of multiple HMIs in water environment.

Pb(II) inhibits CRISPR/Cas12a activation and application for paper-based microfluidic biosensor assisted by smartphone

A simple and low-cost paper-based microfluidic biosensor has been developed for on-site detection of Pb(II) by using CRISPR-Cas12a assisted smartphone device. Pb(II) induced G-quadruplex can inhibit the activation of the CRISPR-Cas12a system and subsequently prevent the cleavage of single-stranded DNA around gold nanoparticles. Thus, the resultant dispersed gold nanoparticles will flow into the detection zone and be subsequently captured by DNA nano-flowers in the detection zone of the paper-based microfluidic chip, resulting in the corresponding color change. The R/G values analyzed through our established SmartIons APP, correlate well with Pb(II) concentrations with a linear detection range of 0.1 μM - 10 μM and a lowest detection limit of 18.3 nM. The paper-based microfluidic biosensor exhibits high specificity, good anti-interference ability, stability and applicability. In view of low cost, easy customization and multiple channel, paper-based microfluidic biosensor has great potential for the on-site detection of Pb(II).

One-pot synthesis of storage-stable, tumor-specific cascade DNA nanobioreactors for ultrasound-promoted synergistic therapy

The application of therapeutic gas to treat tumors is an emerging "green" paradigm. However, the design of high-performace cascade nanobioreactors to convert gas donor into gas molecule in tumor microenvironment still remains challenging. Herein, hierarchical porous DNA nanoflowers (DNF) with programmable sequences are synthesized via one-pot rolling circle amplification, during which glucose oxidase (GOx) and L-arginine (L-Arg) are steadily associated with the polymeric DNA strands and magnesium pyrophosphate crystals. Through encoding of the corresponding aptamer, the as-synthesized storage-stable nanobioreactors L-Arg/GOx@DNF can specifically accumulate into HER2-overexpressed tumors to initialize high-performance cascade catalysis. For the first catalytic stage, GOx in L-Arg/GOx@DNF consumes the energy source of glucose intratumorally to starve tumor cells. Meanwhile, vast toxic H2O2 is generated to aggravate the mitochondrial dysfunction and G2/M phase arrest of vulnerable starved cells. Subsequently, H2O2 further triggers the second stage of catalytic reaction by oxidization of L-Arg into nitric oxide (NO) to synergize with the starvation effect of glucose consumption and chemodynamic effect of H2O2 elevation. Importantly, the external ultrasound irradiation can decompose H2O2 into highly reactive oxygenated species for enhanced oxidation of L-Arg, resulting in the augmented starvation/chemodynamic/gas therapy to synergistically inhibit tumor growth.

DNA self-assembly nanoflower reverse P-glycoprotein mediated drug resistance in chronic myelogenous leukemia therapy.

Introduction: Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disorder caused by the BCR-ABL chimeric tyrosine kinase. Vincristine (VCR) is widely used in leukemia therapy but is hindered by multidrug resistance (MDR). Methods: We prepared DNA nanoflower via self-assembly for the delivery of VCR and P-glycoprotein small interfering RNA (P-gp siRNA). Results and Discussion: The as-prepared nanoflower had a floriform shape with high loading efficiency of VCR (80%). Furthermore, the nanoflower could deliver VCR and P-gp siRNA into MDR CML cells and induce potent cytotoxicity both in vitro and in vivo, thus overcoming MDR of CML. Overall, this nanoflower is a promising tool for resistant CML therapy.

DNA Nanoflower Eye Drops with Antibiotic-Resistant Gene Regulation Ability for MRSA Keratitis Target Treatment.

Methicillin-resistant Staphylococcus aureus (MRSA) biofilm-associated bacterial keratitis is highly intractable, with strong resistance to β-lactam antibiotics. Inhibiting the MRSA resistance gene mecR1 to downregulate penicillin-binding protein PBP2a has been implicated in the sensitization of β-lactam antibiotics to MRSA. However, oligonucleotide gene regulators struggle to penetrate dense biofilms, let alone achieve efficient gene regulation inside bacteria cells. Herein, an eye-drop system capable of penetrating biofilms and targeting bacteria for chemo-gene therapy in MRSA-caused bacterial keratitis is developed. This system employed rolling circle amplification to prepare DNA nanoflowers (DNFs) encoding MRSA-specific aptamers and mecR1 deoxyribozymes (DNAzymes). Subsequently, β-lactam antibiotic ampicillin (Amp) and zinc oxide (ZnO) nanoparticles are sequentially loaded into the DNFs (ZnO/Amp@DNFs). Upon application, ZnO on the surface of the nanosystem disrupts the dense structure of biofilm and fully exposes free bacteria. Later, bearing encoded aptamer, the nanoflower system is intensively endocytosed by bacteria, and releases DNAzyme under acidic conditions to cleave the mecR1 gene for PBP2a down-regulation, and ampicillin for efficient MRSA elimination. In vivo tests showed that the system effectively cleared bacterial and biofilm in the cornea, suppressed proinflammatory cytokines interleukin 1β （IL-1β） and tumor neocrosis factor-alpha （TNF-α）, and is safe for corneal epithelial cells. Overall, this design offers a promising approach for treating MRSA-induced keratitis.

Acid-responsive DNA-Au nanomachine with active/passive dual-targeting capacity for combinational cancer therapy

DNA nanotechnology has attracted intense interest in biomedicine due to the advantages of good biocompatibility, structural programmability and multifunctionality. Herein, a DNA-Au nanomachine with active/passive dual-targeting capacity has been constructed, achieving lysosomal acidic microenvironment-activated combinational chemo-photothermal therapy of cervical carcinoma. The three-dimensional DNA nanoflowers (DNFs) are readily prepared via rolling circle amplification (RCA), in which the active targeting units (C-9S aptamers) for HeLa cells and drug-loading sites for doxorubicin (Dox) are rationally designed in the circular template. Meanwhile, the bovine serum albumin (BSA)-modified gold nanoparticles (BSA-AuNPs) with pH-responsive charge reversal ability are internalized into cancer cells through passive targeting mechanism of enhanced permeability and retention (EPR) effect. Under acidic stimuli (endosome and lysosome), the loaded Dox in DNFs is controllably released for targeted chemotherapy, and the charge of BSA-AuNPs is reversed from negative to positive in lysosome, resulting in the aggregation of BSA-AuNPs on DNFs through electrostatic interaction. Thus, hyperthermia is produced upon 808 nm laser irradiation for photothermal therapy (PTT). The in vitro and in vivo results demonstrate the highly chemo-photothermal therapy effect on cervical cancer based on the proposed DNA-Au nanomachine, providing a powerful and potential nanotheranostic platform for targeted combinational therapy of cancers in clinical applications.

Design of supramolecular hybrid nanomaterials comprising peptide-based supramolecular nanofibers and in situ generated DNA nanoflowers through rolling circle amplification.

The artificial construction of multicomponent supramolecular materials comprising plural supramolecular architectures that are assembled orthogonally from their constituent molecules has attracted growing attention. Here, we describe the design and development of multicomponent supramolecular materials by combining peptide-based self-assembled fibrous nanostructures with globular DNA nanoflowers constructed by the rolling circle amplification reaction. The orthogonally constructed architectures were dissected by fluorescence imaging using the selective fluorescence staining procedures adapted to this study. The present, unique hybrid materials developed by taking advantage of each supramolecular architecture based on their peptide and DNA functions may offer distinct opportunities to explore their bioapplications as a soft matrix.

DNA Nanoflowers' Amelioration of Lupus Symptoms in Mice via Blockade of TLR7/9's Signal.

Inhibitory oligodeoxynucleotides (INH-ODN) can exert an immunomodulatory effect to specifically block TLR7 and TLR9 signaling in systemic lupus erythematosus (SLE). To extend the half-life of INH-ODN in vivo, the phosphorothioate backbone, instead of the native phosphodiester, is preferred due to its strong resistance against nuclease degradation. However, its incomplete degradation in vivo may lead to potential risk. To solve these problems and enhance the blockage of TLR7 and TLR9, we prepared highly compressed DNA nanoflowers with prolonged native DNA backbones and repeated INH-ODN motifs. Three therapeutic types of nanoflower, incorporating INH-ODN sequences, including IRS 661, IRS 869, and IRS 954, were prepared by rolling circle amplification and were subcutaneously injected into MRL/lpr mice. The TLR7 blocker of the IRS 661 nanoflower and the TLR9 antagonist of the IRS 869 nanoflower could decrease autoantibodies, reduce cytokine secretion, and alleviate lupus nephritis in mice. However, the IRS 954 nanoflower, the TLR7 and TLR9 dual antagonist, did not have additive or opposing effects on lupus nephritis but only showed a decrease in serum IFNα, suggesting that the TLR7 and TLR9 antagonist may have a competition mechanism or signal-dependent switching relationship. INH-ODN nanoflowers were proposed as a novel and potential therapeutic nucleic acids for SLE.

Ultrasensitive Automatic Detection of Small Molecules by Membrane Imaging of Single Molecule Assays.

Determination of trace amounts of targets or even a single molecule target has always been a challenge in the detection field. Digital measurement methods established for single molecule counting of proteins, such as single molecule arrays (Simoa) or dropcast single molecule assays (dSimoa), are not suitable for detecting small molecule, because of the limited category of small molecule antibodies and the weak signal that can be captured. To address this issue, we have developed a strategy for single molecule detection of small molecules, called small molecule detection with single molecule assays (smSimoa). In this strategy, an aptamer is used as a recognition element, and an addressable DNA Nanoflower (DNF) attached on the magnetic beads surface, which exhibit fluorescence imaging, is employed as the output signal. Accompanied by digital imaging and automated counting analysis, E2 at the attomolar level can be measured. The smSimoa breaks the barrier of small molecule detection concentration and provides a basis for high throughput detection of multiple substances with fluorescence encoded magnetic beads.

An innovative electrochemical aptasensor based on the dual signal amplification strategy of gold nanowires and bifunctional DNA nanoflowers

Herein, an innovative electrochemical aptasensor based on the dual signal amplification strategy of gold nanowires (AuNWs) as well as bifunctional DNA nanoflowers was designed to detect ochratoxin A (OTA). For the first time, the RCA-induced bifunctional DNA nanoflowers with both target recognition and signal labeling functions were used for OTA detection. The AuNWs was used as the electrode modification material and MB was used as the signal tag. The fabricated aptasensor exhibited a linear range of 1 × 10−4∼10 ng/mL, with limits of detection (LOD, S/N = 3) and limits of quantification (LOQ, S/N = 10) as low as 1.12 fg/mL and 3.73 fg/mL, respectively. This aptasensor exhibited satisfying specificity, reproducibility, stability and repeatability toward OTA detection. This strategy has been successful in detecting OTA in wheat flour, camellia bean, and the good results were also obtained for the quality control samples of corn meal, indicating a new detection model for trace pollutants analysis and environmental monitoring.