Quantum dots based near-infrared fluorescent probe for the detection of PepT1 expression in colorectal cancer

摘要

The lysine-proline-valine tripeptide (KPV) can transport into colorectal cancer (CRC) cells via oligopeptide transporter 1 (PepT1) selectively. Here, we successfully designed a fluorescent probe for PepT1 receptor-targeted CRC imaging. This probe consisted of the CuInS2/ZnS (CIS/ZnS) quantum dots (QDs) conjugated with KPV (QD-PAAO-KPV), exhibiting excellent near-infrared emission characteristics. The in vitro and in vivo results showed that the QD-PAAO-KPV was specifically and efficiently internalized in the PepT1-overexpressing colorectal Caco-2 tumor. In addition, it demonstrated that the probe possessed good biological activities. Thus, this study revealed that the probe QD-PAAO-KPV presented desirable targeting ability, showing promising prospects in CRC detection.