β-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants.The drawbacks of the existing methods are high consumption of both time and reagents,complexity in operation,and requirement of expensive instruments and highly trained personnel.The present study provides a simplified,highly selective,and miniaturized glucometer-based strategy for the detection ofβ-glucosidase activity.Single-factor experiments showed that optimumβ-glucosidase activity was exhibited at 50°C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min.The procedure for detection was simplified without the need of a chromogenic reaction.Validation of the analytical method demonstrated that the accuracy,precision,repeatability,stability,and durability were good.The linear ranges ofβ-glucosidase in a buffer solution and rat serum were 0.0873–1.5498 U/mL and 0.4076–2.9019 U/mL,respectively.The proposed method was free from interference fromβ-dextranase,snailase,β-galactosidase,hemicellulase,and glucuronic acid released by baicalin.This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid(DNS)assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter.Miniaturization of the method resulted in a microassay forβ-glucosidase activity.The easy-to-operate method was successfully used to detect a series ofβ-glucosidases extracted from bitter almonds and cultured by Aspergillus niger.In addition,the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing ofβ-glucosidase in many fields,including medical diagnostics,food safety,and environmental monitoring.
