Development of Low-Cost AuNP-Based Aptasensors with Truncated Aptamer for Highly Sensitive Detection of 8-Oxo-dG in Urine

Piyaporn Matulakul; Drusawin Vongpramate; Sirinan Kulchat; Apiwat Chompoosor; Raynoo Thanan; Paiboon Sithithaworn; Chadamas Sakonsinsiri; Theerapong Puangmali

doi:10.1021/acsomega.0c01834

Development of Low-Cost AuNP-Based Aptasensors with Truncated Aptamer for Highly Sensitive Detection of 8-Oxo-dG in Urine

ACS Omega. 2020 Jul 8;5(28):17423-17430. doi: 10.1021/acsomega.0c01834. eCollection 2020 Jul 21.

Authors

Piyaporn Matulakul¹, Drusawin Vongpramate², Sirinan Kulchat³, Apiwat Chompoosor⁴, Raynoo Thanan^{5

6

7}, Paiboon Sithithaworn^{6

7

8}, Chadamas Sakonsinsiri^{5

6

7}, Theerapong Puangmali¹

Affiliations

¹ Materials Science and Nanotechnology Program, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
² Department of Information Technology, Faculty of Science, Buriram Rajabhat University, Buriram 31000, Thailand.
³ Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
⁴ Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand.
⁵ Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
⁶ Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen 40002, Thailand.
⁷ Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen 40002, Thailand.
⁸ Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.

Abstract

8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), an oxidized form of guanosine residues, is a critical biomarker for various cancers. Herein, a sensitive citrate-capped gold nanoparticle-based aptasensor device has been developed for the detection of 8-oxo-dG in urine. We previously designed a 38-nt anti-8-oxo-dG-aptamer by a computer simulation and the experimental validation has been performed in the present work. The analytical performance of the 38-nt aptamer from the in silico design was compared with the parent 66-nt aptamer. This assay is based on the principle of salt-induced aggregation of citrate-capped gold nanoparticles. Based on this sensing mechanism, the difference between the absorbance in the presence and absence of 8-oxo-dG at λ = 525 nm (ΔA525) increased linearly as a function of 8-oxo-dG concentrations in the ranges of 10-100 and 15-100 nM for 38-nt and 66-nt aptasensors, respectively. This method can provide detection limits of 6.4 nM for 8-oxo-dG in the 38-nt aptasensor and 13.2 nM in the 66-nt aptasensor. Similar to the 66-nt aptamer, the shortened aptamer, 38-nt long, can provide high sensitivity and selectivity with rapid detection time. In addition, using the 38-nt aptamer as a recognition component in the developed portable low-cost device showed high sensitivity in the detection range of 15-100 nM with a detection limit of 12.9 nM, which is much lower than the threshold value (280 nM) for normal human urine. This easy-to-use device could effectively and economically be utilized for monitoring 8-oxo-dG in real urine samples and potentially serve as a prototype for a commercial device.