A method of identifying a target analyte in which a sample containing a light-emitting marker configured to bind to the target analyte is irradiated and emission from the light-emitting marker is detected. The light-emitting marker comprises a light-emitting material comprising a group of formula (I): X is one of N and B and Y is the other of N and B; Ar.sup.1 and Ar.sup.2 independently are an unsubstituted or substituted an aromatic or heteroaromatic group which is unsubstituted or substituted with one or more substituents. Ar1 and Ar2 bound to the same X group may be linked by a direct bond or a divalent group. The group of formula (I) may be a repeat unit of a light-emitting polymer. The light-emitting marker may be used in flow cytometry.

##STR00001##

A high-sensitivity, high-selectivity and portable detection method for trace uranyl ion is described. The method has an ultralow detection limit of 11 pM/2.6 ppt and is useful in precise monitoring of the uranium content in agricultural and sideline products, foods, environments and so on. The test instrument is miniaturized and low in cost to achieve high-precision portable measurement in the field. A conjugated polymer with aggregation-induced emission (AIE) activity is synthesized, and prepared into Pdots, and a uranyl-responsive electrochemiluminescence (ECL) probe is developed by modifying the Pdots with DNA or RNA, which serves as an adsorption ligand of uranyl ion. The probe exhibits good biocompatibility. The ECL technology can be used in uranyl ion detection and the method has extremely high sensitivity. A uranyl ion probe with AIE activity is also disclosed, which can be applied in portable precise monitoring of trace uranyl ion by means of the ECL technology.

In one aspect, electrically conductive conjugated polymeric compositions are described herein demonstrating compatibility with aqueous solvents and/or phases. The ability to provide aqueous compatible compositions from previously water insoluble conjugated polymeric systems, in some embodiments, can facilitate use of such systems in a variety of aqueous applications, including biological applications.

A high-sensitivity, high-selectivity and portable detection method for trace uranyl ion is described. The method has an ultralow detection limit of 11 pM/2.6 ppt and is useful in precise monitoring of the uranium content in agricultural and sideline products, foods, environments and so on. The test instrument is miniaturized and low in cost to achieve high-precision portable measurement in the field. A conjugated polymer with aggregation-induced emission (AIE) activity is synthesized, and prepared into Pdots, and a uranyl-responsive electrochemiluminescence (ECL) probe is developed by modifying the Pdots with DNA or RNA, which serves as an adsorption ligand of uranyl ion. The probe exhibits good biocompatibility. The ECL technology can be used in uranyl ion detection and the method has extremely high sensitivity. A uranyl ion probe with AIE activity is also disclosed, which can be applied in portable precise monitoring of trace uranyl ion by means of the ECL technology.