Novel luteolin sensor of tannic acid-stabilized copper nanoclusters with blue-emitting fluorescence

In this work, the fluorescent copper nanoclusters (Cu NCs) were firstly adopted to detect luteolin with excellent performance. The blue-emitting Cu NCs was successfully prepared through a facile one-pot approach by protection of tannic acid (TA) and chemical reduction of ascorbic acid (AA). The water-soluble nanoclusters possessed uniform size and displayed good stability. The TA-Cu NCs showed maximum luminescence at 434 nm when excited at 366 nm. Based on the static quenching and inner filter effect (IFE) mechanism, the TA-Cu NCs was efficiently and selectively quenched by luteolin. The detection limit was 0.12 μM and linear relationship existed in the range of 0.2-100 μM. Moreover, the TA-Cu NCs probe was successfully employed to detect luteolin in bovine serum samples with satisfactory recoveries. This novel platform was expected to expand the possible detection method based on fluorescence properties.