A strategy of "fluorescence-visualization dual channel" for highly sensitive and rapid detection of phosphate biomarkers based on stimulus-responsive infinite coordination polymers.

The novel stimulus-responsive host-guest nanoparticles were prepared based on lanthanide infinite coordination polymer (COU@Eu-ICPs) for rapid and point-of-care analysis of phosphate (Pi) biomarkers. The obtained COU@Eu-ICPs, which have the host-guest structure, were applied to high-sensitive detection of Pi biomarkers by the means of ratiometric "fluorescence-visualization dual channel". The established method has the advantages of low detection limit (51 nM), wide linear range (0.25–5 μM) and rapid response to Pi within 3 min. The developed sensor was used to detect Pi in normal human urine and serum samples, with the recoveries of 96.04–106.3%. Furthermore, the fluorescent color changes of COU@Eu-ICPs from blue to red can be used to visually inspect Pi by the naked eyes. More importantly, a portable test strip based on COU@Eu-ICPs was fabricated and successfully applied to the rapid visual detection of Pi in human urine and serum samples. [Display omitted] • The novel stimulus-responsive host-guest nanoparticles COU@Eu-ICPs were prepared. • The obtained COU@Eu-ICPs was applied to high-sensitive detection of Pi biomarkers. • The color changes of COU@Eu-ICPs can be used to visually inspect Pi by the naked eyes. • A COU@Eu-ICPs portable test strip was applied to the rapid visual detection of Pi in human urine and serum. [ABSTRACT FROM AUTHOR]