Circulating
tumor-related materials (CTRMs) shed from original
or metastatic tumors, carry a lot of tumor information and are considered
as important markers for cancer diagnosis and metastasis prognosis.
Herein, we report a colorimetric detection strategy for CTRMs based
on aptamer-based magnetic isolation and endogenous alkaline phosphatase
(AP)-signal amplification. This strategy exhibited high sensitivity
and selectivity toward the CTRMs that express AP heterodimers (the
target of aptamer, a potential tumor marker). For clinical samples,
this CTRM assay significantly discriminated colorectal cancer patients
(n = 50) from healthy individuals (n = 39, p < 0.0001). The receiver operating characteristic
(ROC) analysis indicated the sensitivity and specificity reached 92%
and 82%, respectively, at the optimal cutoff point, the area under
the curve of ROC reached 0.93, suggesting great potential for colorectal
cancer diagnosis and therapeutic monitoring. Compared with CTC assays,
this strategy is simple and has the potential for point-of-care testing.