  Fluorescence detection is a commonly used analytical method with the
advantages of fast response, good selectivity and low destructiveness. However,
fluorescence detection, a single-mode detection method, has some limitations,
such as background interference that affects the accuracy of the fluorescence
signal, lack of visualization of the detection results, and low sensitivity for
detecting low-concentration samples. In order to overcome the shortcomings of
fluorescence single-mode detection, we used the dual-mode method of
fluorescence and colorimetry to detect ascorbic acid.
  The dual-mode detection of AA by fluorescence and colorimetry in the probe
system enhances the specificity and accuracy of the detection. This bimodal
detection method solved the problem of low detection sensitivity in the low
concentration range of the analytes to be tested, and was linear in the lower
(0-50 {\mu}M) and higher (50-350 {\mu}M) concentration ranges, respectively,
and had a lower detection limit (0.034 {\mu}M). This glutathione-based gold
cluster assay is characterized by simplicity, rapidity and accuracy, and
provides a new way for the quantitative analysis of ascorbic acid. In addition,
the method was validated during the determination of AA in beverages, which has
the advantages of high sensitivity and fast response time.
