Ultrasensitive all-carbon photoelectrochemical bioprobes for zeptomole immunosensing of tumor markers by an inexpensive visible laser light.
A novel enzyme-free and all-carbon photoelectrochemical (PEC) bioprobe, based on carboxylated multiwalled carbon nanotube-Congo red-fullerene nanohybrids (MWNTCOOH-CR-C60), for the ultrasensitive immunosensing of carcinoembryonic antigen (CEA) was reported. The MWNTCOOH-CR-C60 nanohybrids, prepared by mechanically grinding a mixture of MWNTCOOH, C60, and CR at a certain mass ratio, had good water dispersibility and high PEC conversion efficiency in visible light ranges. Covalent binding of the detection antibody of CEA on the MWNTCOOH-CR-C60 nanohybrids produced a sensitive PEC bioprobe for detection of CEA by sandwich immunosensing. The corresponding immunosensor, employing an inexpensive and portable green laser light, possessed a wide calibration range of 1.0 pg/mL~100.0 ng/mL and a low detection limit of 0.1 pg/mL (calculated 5 zmol for a 10.0 μL sample solution) (S/N = 3), which was successfully applied to the detection of CEA in serum samples from both healthy people and cancer patients. The present work thus demonstrated the promising application of fullerene-based nanocomposites in developing highly sensitive, environmentally friendly, and cost-effective PEC biosensors.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, China.
Chengguo
C
Hu
Jinou
J
Zheng
Xiaoyang
X
Su
Juan
J
Wang
Wangze
W
Wu
Shengshui
S
Hu
D014408:Biomarkers, Tumor / Q000032:analysis*; D002244:Carbon / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007834:Lasers; D057230:Limit of Detection; D046529:Microscopy, Electron, Transmission; D015335:Molecular Probes; D010777:Photochemistry
D014408:Biomarkers, Tumor; D015335:Molecular Probes; D002244:Carbon