目前，基于色谱分离、质谱或光谱的仪器分析技术仍然是准确检测食品中霉菌毒素的主要策略，被国际组织广泛接受为标准化方法[24,25,26]。大型分析仪器通常配备灵敏的检测器和数据分析模块，可以成功检测痕量毒素靶标，具有准确性、重现性和可靠性等优势[27,28]。然而，各种霉菌毒素可能在食品中极低浓度下共存，考虑到食品基质的复杂性，需要在检测过程中纯化食品基质，同时实现低浓度霉菌毒素的富集，以满足仪器分析的要求[29]。为了应对这一挑战，不断开发具有纳米级特征或卓越结构特性的新型纯化材料，并与色谱和质谱等各种大型分析仪器结合使用，实现对复杂食品基质中霉菌毒素的准确灵敏检测[30,31,32]。表2说明了各种纳米级材料在固相萃取（SPE）和固相微萃取（SPME）工艺中检测食品中霉菌毒素的应用。

The SPE process is the most commonly used pretreatment method for complex food matrices, which can purify the matrix and enrich trace substances at the same time. This process requires only a small amount of organic solvent and has good reproducibility [48,49,50]. The property of SPE sorbents determines the effectiveness of SPE as a preprocessing technique [51]. Various nanoscale or microscale materials typically possess a large surface area, enabling the loading of numerous specific recognition groups and achieving specific recognition of trace mycotoxins in complex matrices [52,53]. This requirement is essential for excellent SPE purification materials.

Nano-silica (SiO₂) is easily prepared and possesses a large pore volume and specific surface area. It exhibits excellent hydrophilicity and can be easily surface-modified and combined with other materials [54,55]. As a result, it is widely used as SPE sorbent for the purification of food matrices. Yuan et al. employed humic-acid-bonded silica (HAS) material for the SPE purification of lipid matrices, followed by high-performance liquid chromatography and photochemical post-column reactor fluorescence spectrum (HPLC-PHRED-FLD) to simultaneously quantify aflatoxin (AF) and benzo(a)pyrene (BaP) and evaluated the extraction effectiveness and efficiency [39]. The HAS adsorbent has outstanding adsorption properties due to the large number of functional group hydrogen bonding, hydrophobicity, and π-π interactions, which minimize the pretreatment time and the amounts of organic solvents. It can efficiently and stably adsorb two targets from the lipid matrix and obtain accurate detection results (limits of quantification (LOQs), 0.05–0.30 µg kg⁻¹; limits of detection (LODs), 0.01–0.09 µg kg⁻¹). Compared with a single type of SPE material, the composite SPE material composed of multiple nanoscale materials can combine the advantages of various materials in a targeted manner. This not only helps to improve the purification efficiency but also significantly improves the selectivity of the target compound. Especially in high-throughput, multi-target mycotoxin detection, composite SPE materials have obvious advantages. Wang and his team compared the performance of composite SPE materials composed of different types and dosages of multi-walled carbon nanotubes (MWCNTs) and five different typical adsorbents (i.e., octadecylsilyl (C₁₈), hydrophilic–lipophilic balance (HLB), mixed-mode cationic exchange (MCX), silica gel, and amino-propyl (NH₂)) in purifying corn and wheat matrices and extracted a total of 21 mycotoxins [41]. The combination of MWCNTs (20 mg) and C₁₈ (200 mg) was demonstrated to be the most effective, significantly reducing the matrix effect, enabling the high-throughput screening of various mycotoxins, and greatly improving the detection efficiency. The study of Han et al. combined carbon-based nanomaterial graphene (rGO) with stable chemical properties, a high specific surface area, and a strong adsorption capacity with gold nanoparticles (AuNPs), which effectively overcame its irreversible aggregation problem in solution [36]. Compared with commercial SPE materials, their novel nanoadsorbent rGO/AuNPs showed comparable or even better adsorption and purification effects at a lower cost. A satisfactory linear quantification range (0.02–0.18 ng mL⁻¹, R² ≥ 0.992) was obtained for nine mycotoxins in milk in combination with ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) analysis, which laid the foundation for the further development of an effective method for high-throughput and rapid screening of multi-mycotoxins. Although such nanoscale composite SPE materials have largely enhanced the purification and detection rates, they are not specific enough to accurately purify or enrich for a single mycotoxin. Therefore, the development of nanoscale pretreatment materials that are both efficient and specifically recognized for the extraction of mycotoxins from food products is of great importance.

Molecularly imprinted polymers (MIPs) are a class of chemically synthesized materials with the specific recognition capability to target molecules, which are called “artificial antibodies (Abs)” [56,57,58]. Due to the remarkable stability and selectivity, MIPs have been widely used as sorbents for the extraction of various chemical substances [59,60,61]. Dalibor’s team compared the prepared MIPs with selective recognition and binding sites for zearalenone (ZEN) with the non-selective reversed-phase C₁₈ extractant and evaluated the difference in the analytical characteristics of the two extractants during the extraction process [62]. Due to the use of online SPE, the two detection strategies based on the high-performance liquid chromatography (HPLC) of MIPs or C₁₈ absorbents established in this study overcame the drawbacks of time-consuming and manual sample pretreatment in ZEN detection. Unfortunately, the two SPE detection strategies were similar in terms of linear range, sensitivity, reproducibility, and even no significant difference in specificity identification, which was inferred to be caused by the strong affinity of the esterophilic target ZEN on the C₁₈ sorbent. Metal–organic frameworks (MOFs) are a class of crystalline materials formed by the coordination of metal ions or clusters with organic ligands [63,64]. They are characterized by a high specific surface area, large porosity, ease of synthesis, thermal stability, and tenability [65,66]. Liang’s team attached MIPs to the surface of MOF material UiO-66-NH₂ via the precipitation aggregation method as an adsorbent for SPE, which was used for the adsorption and quantification of aflatoxins (AFB₁, AFB₂, AFG₁, and AFG₂) in grains, and the adsorption capacity was compared with that of commercial SPE [40]. In this study, the surface of UIO-66-NH₂ was modified by grafting glycidyl methacrylate (GMA), which effectively preserved the interaction between the monomer and the virtual template and formed hydrogen bonding sites. The prepared novel surface-imprinted polymer materials were uniform and stable, and the unique pore structure could effectively improve the selective adsorption capacity of polymer materials. Secondly, due to the large specific surface area of MOFs and the high specificity of MIPs, it shows excellent affinity and selectivity for aflatoxins, and it is a rapid, cheap, efficient, and reusable method. Unfortunately, although the problem of high cost and high toxicity of the target as a template has been solved, it still fails to selectively adsorb a single target substance.

Magnetic SPE is a new SPE method that has attracted extensive attention in the field of separation science because of its convenient, rapid, and efficient adsorption separation in a magnetic field [67,68]. Magnetically functionalized nanomaterials such as metal oxides, polymers, and organic frameworks are used in enrichment and separation processes for different targets [69,70,71]. Covalent organic frameworks (COFs) are a new type of crystalline material with the advantages of a large specific surface area, high porosity, abundant functional groups, and good thermal and chemical stability [72,73]. They can be combined with magnetic nanoparticles to increase pretreatment extraction materials’ porosity and specific surface area. In the study of Nie et al. [34], a magnetic COF nanomaterial Fe₃O₄@COF (TAPT-DHTA) was prepared via a simple template precipitation polymerization method, which was applied to simultaneously enrich nine mycotoxins in fruits. Combined with the analysis of ultrahigh-performance liquid chromatography in combination with tandem mass spectrometry (UHPLC-MS/MS), a wide linear range (0.05–200 μg kg⁻¹) and a low LOD (0.01–0.5 μg kg⁻¹) for nine targeted mycotoxins were achieved. Notably, the Fe₃O₄@COF adsorbent prepared in the study was rich in aromatic rings and carbonyl groups and, thus, can effectively enrich the target toxins through strong π-π interactions and hydrogen bonding. Zhang et al. [74] designed an effective magnetic COF sorbent using two novel monomers of 1,2,4,5-Tetrakis-(4-formylphenyl) benzene (TFPB) and p-Phenylenediamine (PPD) at room temperature. The adsorption capacities for AFs ranged from 69.5 to 92.2 mg g⁻¹. Under the optimized conditions, the SPE extraction efficiency was enhanced, saving both time (5 min) and organic reagent (2 mL), and satisfactory results for AF detection in food matrices (milk, edible oil, and rice) were obtained. The magnetic COF sorbent can be reused more than eight times. Wei et al. [75] developed a vortex-assisted magnetic SPE method, using a core–shell structured magnetic covalent organic skeleton (FeO/COF-TpBD) as the adsorbent for rapid and simultaneous extraction of ten mycotoxins commonly found in maize. The prepared magnetic adsorbent was demonstrated to have the advantages of strong magnetism and good stability, which also obtained high sensitivity (LOD: 0.02–1.67 μg kg⁻¹) and recovery (73.8–105.3%). Furthermore, the adsorbent dosage (5 mg) and required time (0.5 min each for adsorption and desorption) were greatly shortened compared with previous reports. Due to the complexity of the food matrices and the rapid consumption of food, magnetic SPE sorbents are required to have good chemical stability, strong dispersion ability, and a high affinity for mycotoxins. These attributes are crucial for ensuring the efficiency and reproducibility of magnetic SPE purification process. Therefore, magnetic SPE adsorbents used for food matrices’ purification are typically designed as core–shell structures. That means functionalizing the surface of the magnetic core to form a specific recognition shell with high affinity for the targets. The preparation of such core–shell magnetic SPE adsorbents involved multiple complex steps, leading to significant batch-to-batch variations, which limited the widespread application of these materials to some extent. Additionally, the magnetic properties may decrease after multiple modifications on the surface of magnetic nanoparticle core, directly affecting the efficiency of adsorption and separation. Therefore, it is necessary to develop magnetic SPE materials that are easy to prepare, possess stable magnetic properties, and exhibit a high affinity for the target compounds.

In contrast to traditional SPE technology, SPME greatly simplifies the analytical operation procedure, reduces the extraction time, and enhances the extraction efficiency, and it has been emphasized in food detection [76,77,78]. Nanomaterial-based novel solid-phase adsorbent materials possess a larger specific surface area, suitable pore size, and surface structure, along with excellent adsorption and mechanical properties [79,80]. These features enable the highly selective adsorption of target analytes in complex matrices, showing great potential for application in SPME [81]. This provides crucial support for the rapid and highly sensitive detection of mycotoxins.

金纳米颗粒（AuNPs）由纳米级金原子（1-100nm）组成，不仅具有独特的光学、电学和优异的表面增强性能，而且还具有高比表面积。AuNPs可用作Abs、适配体和其他特异性识别分子的载体，使其成为食品检测领域最常用的材料[82,83,84]。Zhang等人提出了一种简单可控地制备适配体官能化毛细管单片聚合物杂化物的创新方法，该方法在食品样品中棒曲霉素的测定中实现了高特异性和高亲和力[43]。含有棒曲霉素适配体的AuNPs通过毛细管单片柱上的Au-S键直接修饰。这些适配体官能化的毛细管单体-聚合物杂化材料作为SPME吸附剂组合UPLC-MS/MS应用，对棒曲霉素具有非常高的灵敏度和选择性，LOD为2.17 pmol L⁻¹线性范围为 0.0081–8.11 nmol L⁻¹.基于甲基丙烯酸和二乙烯基苯的共聚合反应，Wu等人开发了一种聚（甲基丙烯酸-共-二乙烯基苯）[聚（MAA-co-DVB）]整体式柱，用于三种霉菌毒素的管内SPME[44]。由两种聚合物单体形成的高强度微纳米结构中含有大量丙烯酸基团，能够与AFB结构中的羰基、羟基和疏水苯基团形成氢键₁、禅宗和孕孢子虫素。因此，所开发的基于聚（MAA-co-DVB）的整体柱对3个靶分子具有较高的识别能力，有效克服了大米食品的基质效应，实现了对3种靶标霉菌毒素的高灵敏度测定。

碳基纳米材料、MOF和MIP是SPME中常用的一些材料[92,93,94]。它们具有独特的纳米结构和优异的理化性质，有助于提高复杂基质提取过程的分析效率、选择性和灵敏度，广泛应用于霉菌毒素的检测[95,96]。石墨烯是一种典型的碳基纳米材料，表面具有丰富的含氧官能团（-OH和-COOH）。这些官能团可以与目标分子形成氢键或静电相互作用，从而促进吸附过程[97,98]。此外，石墨烯表面的改性可以减少团聚现象，增强其吸附能力。Wu等人通过水热工艺制备了还原rGO和ZnO纳米复合材料（rGO-ZnO），用于分离、纯化和富集12种霉菌毒素[99]。对影响DSPME的关键参数进行了详细的优化，包括提取液、淋洗液和吸附剂用量，以获得理想的纯化和提取效率。结合UHPLC-MS/MS，将制备的rGO-ZnO材料用于12种霉菌毒素靶标的提取和分析，实现了高灵敏度（LOQ：0.09–0.41 μg kg⁻¹）和令人满意的精度（RSD：1.4–15.0%）。MOF材料具有极高的孔隙率、优异的热稳定性和较大的比表面积。其可调孔径、多孔通道和纳米空间使其成为理想的SPME吸附材料。Lotfipour及其同事[46,47]使用维生素B制备了一种基于维生素的MOF材料。₃作为生物接头和钴离子作为水中的金属中心，并将其作为吸附剂应用于果汁样品和四种黄曲霉毒素（AFB）的棒曲霉素和赭曲霉毒素A（OTA）的DSPME中₁， 空军基地₂， AFG₁和 AFG₂） 来自豆浆。通过将沉淀的蛋白质上清液与吸附剂混合并简单地涡旋和离心，可以实现高提取效率。该MOF材料对目标霉菌毒素表现出优异的吸附能力，可以以环保的方式大规模制备。所开发的策略在萃取过程中只需要少量的吸附剂和有机溶剂，这是其显着优势之一。利用微流控自组装技术，Wang等人成功制备了具有规则三维有序大孔结构的磁性逆光子微球，并进一步利用“虚拟模板”分子印迹法制备了具有高选择性的MIP[100]。该MIP材料具有孔径可调、易改性、光子晶体微球热稳定性好等优点，可作为DSPME吸附剂与HPLC联合使用，实现AFB的快速定量分析₁.