This study aimed to construct a highly sensitive, reliable, and low-cost electrochemical sensor based on graphitic carbon nitride (g-C3N4) modified materials for efficient and convenient detection of purine content in edible mushrooms. The g-C3N4 material was fabricated through a high-temperature calcination method, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The results indicated that the g-C3N4 material exhibited a two-dimensional sheet-like nanostructure, characterized by a high degree of graphitization, abundant N-functional group content, and a specific surface area of 61.35 m2/g. An electrochemical sensor (g-C3N4/GCE) was fabricated by modifying a glassy carbon electrode (GCE) with the composite material. Under optimal conditions (pH5.5, enrichment potential of 0.3 V, and enrichment time of 5 min), the peak current of the sensor demonstrated a favorable linear relationship with the concentration of xanthine. Within the low concentration range of 0.5~5 μmol/L, a linear relationship was established as Ipa=0.310CXA+2.859 (where Ipa represented the peak current and CXA denoted the xanthine concentration), with a coefficient of determination R2=0.990. In the high concentration range of 5~200 μmol/L, the linear relationship was determined to be Ipa=0.051CXA+4.034, with R2=0.997. The minimum detection limit (LOD) was calculated to be 0.28 μmol/L. According to this sensor, the xanthine content in shiitake mushrooms, tea tree mushrooms, and wood ears were 307.50, 229.22, and 47.27 mg/100 g, respectively. Compared with the commonly used high-performance liquid chromatography method, the g-C3N4 electrochemical sensor exhibited good stability, with a relative standard deviation (RSD) of 1.45%~3.69%, and the operation was simple, which could be used for the detection of xanthine in edible mushrooms.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |