Lateral flow chromatography strip system for rapid fluorescence determination of phycocyanin in water samples

Phycocyanin (PC) is of great significance to biomedicine and water environmental safety. Hence, it is indispensable to develop facile and rapid method for PC determination. In this investigation, a system containing lateral flow chromatography (LFC) strip (which was deposited with molecularly imprinted polymer (MIP) capped CdTe quantum dots (QDs) based mesoporous structured coated silica nanoparticles, SiO₂@QDs@ms-MIP NPs) and miniaturized fluorimeter was first fabricated. In detail, a two-step strategy was utilized for preparation of SiO₂@QDs@ms-MIP NPs, which consisted of modification of CdTe QDs onto the silica NPs first, and synthesis of mesoporous imprinting shell by using PC as template molecule and cetyltrimethylammonium bromide (CTAB) as surfactant. After that, novel fluorescence NPs possessing specific recognition and sensitivity toward PC in seawater and lake water were acquired. The resulting fluorescent sensing system exhibited outstanding performances, which included excellent sensitivity (4.5 nmol/L), satisfactory specificity (imprinting factor, 2.31), appropriate linearity range (0.01-5 μmol/L), good recovery (96.0-101.7 %), excellent stability (relative standard deviation, RSD<1.1 %), wonderful reproducibility (RSD<1.1 %), and excellent anti-interference ability. The results of the fluorescent sensing system were superior to those of the commonly used ultraviolet (UV) method. The proposed strategy showed great potential for fast (<10 min) and convenient fluorescence detection of PC in real samples.