Dual-signal output biosensor for the detection of program death-ligand 1 and therapy progress monitoring of cancer.

A disposable dual-output biosensor to detect program death-ligand 1 (PD-L1) was developed for immunotherapy progress monitoring and early cancer detection in a single experimental setup. The aptamer probe was assembled on rGO composited with carboxylated terthiophene polymer (rGO-pTBA) to specifically capture PD-L1 protein labeled with a new redox mediator, ortho-amino phenol para sulphonic acid, for amperometric detection. Each sensing layer was characterized through electrochemical and surface analysis experiments, then confirmed the sensing performance. The calibration plots for the standard PD-L1 protein detection revealed two dynamic ranges of 0.5-100.0 pM and 100.0-500.0 pM, where the detection limit was 0.20 ± 0.001 pM (RSD ≤5.2%) by amperometry. The sensor reliability was evaluated by detecting A549 lung cancer cell-secreted PD-L1 and clinically relevant serum levels of soluble PD-L1 (sPD-L1) using both detection methods. In addition, therapeutic trials were studied through the quantification of sPD-L1 levels for a small cohort of lung cancer patients. A significantly higher level of sPD-L1 was observed for patients (221.6-240.4 pM) compared to healthy individuals (16.2-19.6 pM). After immunotherapy, the patients' PD-L1 level decreased to the range of 126.7-141.2 pM. The results indicated that therapy monitoring was successfully done using both the proposed methods. Additionally, based on a comparative study on immune checkpoint-related proteins, PD-L1 is a more effective biomarker than granzyme B and interferon-gamma.

Conducting polymer composite-based biosensing materials for the diagnosis of lung cancer: A review.

The development of a simple and fast cancer detection method is crucial since early diagnosis is a key factor in increasing survival rates for lung cancer patients. Among several diagnosis methods, the electrochemical sensor is the most promising one due to its outstanding performance, portability, real-time analysis, robustness, amenability, and cost-effectiveness. Conducting polymer (CP) composites have been frequently used to fabricate a robust sensor device, owing to their excellent physical and electrochemical properties as well as biocompatibility with nontoxic effects on the biological system. This review brings up a brief overview of the importance of electrochemical biosensors for the early detection of lung cancer, with a detailed discussion on the design and development of CP composite materials for biosensor applications. The review covers the electrochemical sensing of numerous lung cancer markers employing composite electrodes based on the conducting polyterthiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, molecularly imprinted polymers, and others. In addition, a hybrid of the electrochemical biosensors and other techniques was highlighted. The outlook was also briefly discussed for the development of CP composite-based electrochemical biosensors for POC diagnostic devices.

The feasibility of granzyme B levels using an amperometric immunosensor for lung cancer detection.

Background: Low-dose computed tomography (LDCT) has improved the early detection of lung cancer. However, LDCT scans present several disadvantages, including the abundance of false-positive results, which lead to a high socioeconomic cost, psychological burden, and repeated exposure to radiation. Therefore, the identification of complementary biomarkers is needed to select high-risk individuals for LDCT. Here, we showed that granzyme B testing with the novel immunosensor has diagnostic value for identifying patients with lung cancer. Methods: We enrolled 44 patients with lung cancer and 51 health controls at Pusan National University Yangsan Hospital in Korea between March 2018 and September 2019. The immunosensor analyzed serum granzyme B levels, and their association with lung cancer detection was evaluated with machine learning models. Results: Serum granzyme B levels were assessed in samples from patients with lung cancer and healthy individuals. Granzyme B testing showed 100% sensitivity, 80% specificity, and an area under the curve of 0.938 for lung cancer detection. After combining granzyme B testing with clinical predictors such as age, smoking status, or pack-years, results from the five-fold cross-validation with random forest model improved diagnostic accuracy of 92.1%, with a sensitivity, specificity, and area under the curve of 92.0%, 92.1%, and 0.977, respectively. Conclusions: This feasibility study suggested that granzyme B may be utilized to detect lung cancer.

Disposable amperometric immunosensor with a dual monomers-based bioconjugate for granzyme B detection in blood and cancer progress monitoring of patients.

A disposable amperometric biosensor with a dual monomers-based bioconjugate was developed for granzyme B (GzmB) detection and for monitoring of the cancer progression of patients before and after immunotherapy. The biosensor was fabricated by immobilizing a GzmB monoclonal antibody (Ab1) on a poly3'-(2-aminopyrimidyl)-2,2':5',2''-terthiophene/gold nanoparticle (pPATT/AuNP) layer. The bioconjugate nanoparticles were synthesized through self-assembly of a monomer mixture of 2,2:5,2-terthiophene-3-(p-benzoic acid) (TBA) and PATT onto AuNPs, followed by chemical binding of brilliant cresyl blue (BCB) on TBA and GzmB polyclonal antibody (Ab2) on the PATT layer. Each sensing layer was investigated by surface analysis and electrochemical experiments. The sensor performance was assessed with selectivity, stability, reproducibility, detection limit, and real sample analysis. Under the optimized conditions, the dynamic range of GzmB was in two slopes from 3.0 to 50.0 pg/ml and from 50.0 to 1000.0 pg/ml with a detection limit of 1.75 ± 0.14 pg/ml (RSD ≤5.2%). GzmB monitoring was performed for the patient's serum samples, where a low level of GzmB was observed for lung cancer patients before immunotherapy (10.51 ± 0.99 pg/ml, RSD ≤6.2%), and the level was increased after therapy (17.19 ± 2.22 pg/ml, RSD ≤2.6%). Moreover, a significantly higher level was present in healthy persons (34.40 ± 3.92 pg/ml, RSD ≤1.4%). The cancer progression of patients before and after therapy was evaluated by monitoring GzmB levels in human serum using the proposed sensor.