Squamous Cell Carcinoma Antigen Concentrations Research Articles

Prognostic evaluation of relapse based on squamous cell carcinoma antigen, CXCR2, and CD44V6 blood levels in patients with Stage I–II squamous cell lung cancer

Lung cancer, the leading cause of cancer-related mortality, predominantly exists as non-small cell lung cancer, accounting for approximately 85% of cases and comprising adenocarcinoma, squamous cell carcinoma (SCC), and large cell carcinoma as the three most prevalent histological subtypes. This study focused on investigating pre- and post-operative concentrations of SCC antigen in blood serum, as well as the percentage of CXCR2-containing lymphocytes and CD44v6-containing monocytes in blood cell populations among patients with Stages I–II squamous cell lung cancer (SCLC) within 1 year after tumor resection. The primary objective was to assess their potential for predicting relapse. The study cohort comprised 57 patients (32 men and 25 women) with newly diagnosed squamous cell lung cancer (21 at stage I and 36 at stage II). Following tumor resection, categorized as R0 in terms of surgical intervention, all parameters were examined before surgery and at 3 weeks, 3 months, and 6 months postoperatively. Analysis revealed that the probability of relapse could be accurately predicted, ranging from 68.4% to 89.5%, based on differences in SCC antigen concentration, the percentage of lymphocytes with CXCR2, and monocytes with the CD44v6 receptor during various post-operative intervals. Subsequent regression analysis and the formulation of a combined model incorporating the above-mentioned parameters led to an enhanced predictive value for tumor recurrence, reaching 96.5% accuracy (with specificity at 95.6% and sensitivity at 100%). These results indicate the potential utility of the combined model as an additional marker for predicting postoperative relapse in patients with Stage I–II SCLC.

Predictive value of serum SCCA and CYFRA21-1 levels on radiotherapy efficacy and prognosis in patients with non-small cell lung cancer

ABSTRACT Monitoring changes in serum tumor marker concentrations can help in the early diagnosis of non-small cell lung cancer (NSCLC). However, there are few methods to monitor the efficacy and prognosis of radiotherapy in NSCLC patients. The present research aimed to explore the correlation between radiotherapy efficacy and squamous cell carcinoma antigen (SCCA) and cytokeratin 19 soluble fragment (CYFRA21-1) levels in NSCLC patients. Serum CYFRA21-1 and SCCA were detected with an automatic chemiluminescence immunoassay analyzer. Patients with NSCLC were followed up by telephone at regular intervals for 35 months. The χ2 test was used to compare clinical characteristics such as age, gender, smoking history and other count data between groups. Predictive value of serum SCCA and CYFRA21-1 on the efficacy of radiotherapy was analyzed by Receiver Operating Characteristic (ROC) curves. The survival of the patients was analyzed by Kaplan–Meier method. The serum SCCA and CYFRA21-1 levels in the NSCLC group were apparently higher by comparison with control group. The SCCA and CYFRA21-1 concentration were both positive relevant to Tumor Node Metastasis (TNM) stage. The Area Under Curve (AUC) of serum SCCA and CYFRA21-1 were 0.732 and 0.721, respectively. In addition, high serum SCCA and CYFRA21-1 levels could predict poor radiotherapy outcomes. Patients with high serum concentration of SCCA and CYFRA21-1 have shorter survival times. High serum SCCA and CYFRA21-1 levels could predict poor prognosis and unfavorable efficacy of radiotherapy in invalids with NSCLC.

Correlation between HRCT signs and levels of CA125, SCCA, and NSE for different pathological types of lung cancer.

The aim of this study was to investigate the correlation between high-resolution CT (HRCT) signs and serum tumor markers, to improve the diagnostic level and identify different pathological types of lung cancer. 102 patients with pathologically confirmed lung cancer were selected as the observation group. HRCT scan and serum tumor markers [cancer antigen 125 (CA125), squamous cell carcinoma antigen (SCCA), and neuron-specific enolase (NSE)] were performed to analyze the correlation. Among the 102 cases of lung cancer, 88 cases were of lobulation sign, 78 cases of speculation sign, 45 cases of pleural indentation sign, 35 cases of vessel tracking sign, and 34 cases of vacuole sign. CA125 had the highest concentration in lung adenocarcinoma (55.74±14.18) ng/ml, and SCCA had the highest concentration in lung squamous cell carcinoma (18.98±6.37) ng/ml. The concentration of NSE in small cell lung cancer was the highest (48.12±16.19) ng/ml. Pleural indentation sign and vacuole sign were more likely to happen in lung adenocarcinoma and lung squamous cell carcinoma, respectively. The significant increase of CA125, SCCA, and NSE concentrations suggested that lung cancer patients were more likely to suffer from lung adenocarcinoma, lung squamous cell carcinoma, and small cell lung cancer, respectively.

Photoelectrochemical immunoassay of squamous cell carcinoma antigen based on CuO/nitrogen-doped porous carbon-ZnO biolabeling and a type-II In2O3/AgBiS2 heterojunction.

AgBiS2 was hydrothermally synthesized, In2O3 was synthesized by hydrothermal method and calcination, and the type-II In2O3/AgBiS2 heterojunction material of an optimized composition ratio was cast-coated on a fluorine-doped tin oxide (FTO) slice to fabricate an In2O3/AgBiS2/FTO photoanode. The signal-attenuated photoelectrochemistry sandwich immunoassay of squamous cell carcinoma antigen (SCCA) was realized on this photoanode, on the basis of a bovine serum albumin/secondary antibody/CuO nanoparticles/nitrogen-doped porous carbon-ZnO bionanocomposite that can competitively absorb light and deplete the electron donor ascorbic acid as well as show the steric hindrance and p-n quenching effects. Under the optimized conditions (e.g.,at a bias of 0 V vs. SCE), the photocurrent was linear with the common logarithm of SCCA concentration from 2.00 pg mL-1 to 50.0 ng mL-1, with a limit of detection (LOD) of 0.62 pg mL-1 (S/N = 3). The immunoassay of SCCA in human serum samples gave satisfactory recovery (92.0~103%) and relative standard deviation (5.1~7.8%) results.

High Sensitive and Specific Detection of SCCA via Halloysite Nanotube Modified Terahertz Metasurface Sensor

Squamous cell carcinoma antigen (SCCA) level is an auxiliary indicator for lung cancer diagnosis and predictive monitoring, and its standard reference value is less than 1.5 ng/mL. Therefore, achieving high sensitivity and specific detection of the SCCA is a challenge. In this work, we designed a double split-ring-resonator (SRR) terahertz (THz) metasurface sensor. Simulation results show that the sensitivity of the sensor can reach 103 GHz/RIU (refractive index unit). After the sensor is modified with different concentrations of halloysite nanotubes (HNTs), the resonant frequency of the sensor exhibits different linear responses to different concentrations of SCCA. The optimum concentration of HNTs to enhance the detection performance of the sensor was obtained as 10 mg/mL. The linear range of SCCA concentration of the HNT modified sensor was 1 pg/mL to 100 ng/mL. On this basis, we modified anti-SCCA on the sensor, and other biomarkers of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), CA125, and CA199 were used as comparisons. The results indicated that the sensor modified with HNTs showed a more remarkable frequency shift for the SCCA, which verified that the sensor had good specificity for the SCCA. Therefore, this sensor can be used for highly sensitive and specific detection of the SCCA.

SCC Antigen Concentrations in Fine-Needle Aspiration Samples to Detect Cervical Lymph Node Metastases: A Prospective Analysis.

To determine the diagnostic value of measuring squamous cell carcinoma antigen (SCC-Ag) and cancer antigen 15-3 (CA15-3) concentrations in fine-needle aspiration (FNA) samples for the detection of squamous cell carcinoma (SCC) metastases in cervical lymph nodes. A prospective study with patients consecutively included between November 2018 and May 2021. A tertiary head and neck oncologic center. Out of 138 patients, SCC-Ag concentrations were analyzed in 168 FNA cervical lymph node samples and CA15-3 in 152 samples. Results were compared with FNA cytology (FNAC) or definitive histology to establish sensitivity and specificity rates. For the detection of cervical SCC lymph node metastases, SCC-Ag measurement had an 89.4% sensitivity and 79.3% specificity at a cutoff concentration of 0.1 µg/L. Measurement of CA15-3 concentration in addition to SCC-Ag concentration did not lead to improved accuracy for the detection of SCC. In histology-confirmed cases, FNAC had an 80.0% sensitivity and 100% specificity, as opposed to 93.3% and 57.1%, respectively, for SCC-Ag. Measurement of SCC-Ag concentration for detection of SCC lymph node metastases has a sensitivity at least comparable to FNAC and could be used as a relatively cheap screening tool in samples with nondiagnostic or indeterminate FNAC results or when multiple lymph nodes are sampled. However, SCC-Ag in FNA samples has a lower specificity than FNAC assessed by pathologists experienced in head and neck oncology. Addition of CA15-3 measurement did not lead to improved accuracy.

Improving the diagnostic efficacy of squamous cell carcinoma antigen for oral squamous cell carcinoma via saponin disruption of serum extracellular vesicles

BackgroundThe diagnostic value of squamous cell carcinoma antigen (SCCA) for oral squamous cell carcinoma (OSCC) is insufficient. Recently, extracellular vesicles (EVs) have displayed great potential for improving diagnostic efficacy. However, one of the main challenges that restricts the application of EVs is the lack of a clinically suitable separation method for the intra-vesicular protein detection. MethodsSaponin was used to destroy serum EVs membranes for releasing the intra-vesicular SCCA into the serum, circumventing the purification process of EVs. The concentrations of SCCA were measured and compared in 113 healthy people and 73 OSCC patients pre- and post-saponin treatment. ResultsThe concentration of serum SCCA significantly increased after saponin destroyed the membrane of EVs. The area under the curve (AUC) of serum SCCA for OSCC diagnosis was 0.6444 (95% CI, 0.5595 to 0.7293). The diagnostic AUC of serum EVs-derived SCCA reached 0.7969 (95% CI, 0.735 to 0.8588). ConclusionsThe results suggested that serum EVs disrupted by saponin could improve the diagnostic efficacy of SCCA for OSCC, which provides a simple, rapid, and high-throughput method to detect the intra-vesicular proteins of EVs and holds great potential for clinical application.

Combined Detection of ACTN4 and SCC-Ag is a Promising Serological Biomarker for Cervical Intraepithelial Neoplasia 3 or Worse: A Case-Control Study.

PurposeCervical cancer (CC) is a common malignancy in women. Squamous cell carcinoma antigen (SCC-Ag) and cancer antigen (CA)-125 are widely used to help diagnose CC, but novel tumour markers with superior sensitivity and specificity are needed. α-Actinin 4(ACTN4) is overexpressed in CC, though its diagnostic value for CC is unclear. This study examined the diagnostic value of ACTN4 and SCC-Ag as biomarkers for cervical intraepithelial neoplasia (CIN) 3 or worse.MethodsWomen screened for CC at Fujian Medical University Union Hospital were recruited from 2017.1 to 2018.5. Cervical tissues and blood were collected at the same time. Patients pathologically diagnosed as CIN3+ or NILM/CIN1/CIN2 were classified into the case and control groups, respectively. ACTN4 mRNA and protein levels were detected through quantitative PCR and immunohistochemistry, respectively, and ACTN4 and SCC-Ag concentrations were analysed by ELISA. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood rate (PLR), negative likelihood rate (NLR), and Youden index (YI) of ACTN4 and SCC-Ag were evaluated. The optimum cut-off points for ACTN4 and SCC-Ag were determined by receiver operating characteristic (ROC) curve analysis, and accuracy was evaluated by the area under the ROC curve.ResultsIn total, 105 patients were classified as CIN3+ cases and 106 as controls. The median ACTN4 levels in case and control tissues were 10.6 and 4.15, respectively. The ACTN4 and SCC-Ag concentrations were significantly higher in cases than controls (PACTN4=0.0007; PSCC-Ag=0.0067). The sensitivity, specificity, PPV, NPV, PLR, NLR and YI of ACTN4 were 68.6%, 76.3%, 76.3%, 72.5%, 2.89, 0.41 and 44.9, respectively; SCC-Ag had a similar diagnostic value (P>0.05), and ACTN4 combined with SCC-Ag had a superior diagnostic value (75.6%, 87.5%, 88.6%, 73.7%, 6.05, 0.28, and 63.1, respectively).ConclusionCombined ACTN4 and SCC-Ag detection is a promising serological biomarker for patients with CIN3 or worse.

Expression levels of SCCA and CYFRA 21-1 in serum of patients with laryngeal squamous cell carcinoma and their correlation with tumorigenesis and progression.

To explore the concentration of squamous cell carcinoma antigen (SCCA), cytokeratin fragment antigen21-1 (CYFRA21-1) in patients with laryngeal squamous cell carcinoma (LSCC) and its correlation with tumorigenesis and progression. A total of 78 patients with LSCC admitted to our hospital from February 2010 to January 2016 were enrolled as the research group (RG), and another 41 healthy volunteers from the same period were selected as the control group (CG). The serum concentrations of SCCA and CYFRA21-1 in patients with LSCC were detected by ELISA, whose diagnostic value in LSCC were further analyzed by ROC curve. The prognosis and survival curves of patients with LSCC were observed according to the median value of serum SCCA and CYFRA21-1 concentrations. The concentration of CYFRA21-1 and SCCA in the RG was significantly higher than that in the CG (p < 0.050). The SCCA and CYFRA21-1 identified a significant difference in smoking, lymphatic metastasis, TNM staging, and differentiation degree (p < 0.050). The survival rate of the SCCA low-concentration group was significantly better than that of the high-concentration group, p < 0.050. The survival rate of the CYFRA21-1 low-concentration group was markedly better than that of the high-concentration group, p < 0.050. SCCA and CYFRA21-1 are highly concentrated in LSCC patients, which have good diagnostic efficacy for LSCC. In addition, they play some certain role in the occurrence and development of LSCC, and are expected to be markers for early diagnosis and prognosis of this disease.

Optimized Cutoff Value of Serum Squamous Cell Carcinoma Antigen Concentration Accurately Predicts Recurrence After Curative Resection of Squamous Cell Carcinoma of the Esophagus.

Squamous cell carcinoma antigen (SCC-Ag) and carcinoembryonic antigen (CEA) are widely used in clinical practice to predict the prognosis of patients with esophageal squamous cell carcinoma (ESCC). However, their predictive values for prognosis are controversial. This study determined optimal cutoff values of serum SCC-Ag and CEA concentrations for predicting postoperative recurrence of ESCC, which enabled selection of high-risk patients. The study retrospectively analyzed 427 patients who underwent curative resection for ESCC. The optimal cutoff values of preoperative SCC-Ag and CEA concentrations for predicting postoperative recurrence were determined using combined analysis of hazard ratios and sensitivities for recurrence. Using the optimal cutoff value, the study evaluated survival, recurrence patterns, and temporal changes in marker concentrations. The preoperative SCC-Ag concentration of 1.1ng/ml was the optimal cutoff value for predicting postoperative recurrence, whereas precise cutoff values could not be determined for preoperative CEA concentrations. High preoperative SCC-Ag concentrations (> 1.1ng/ml), which were significantly associated with more aggressive tumor phenotypes and shorter disease-free survival, were identified as an independent prognostic factor in the multivariable analysis. High preoperative SCC-Ag concentrations were significantly associated with greater prevalence of lung/pleura and local recurrences. Normalization of serum SCC-Ag concentrations after neoadjuvant treatment or esophagectomy was not associated with a decreased risk of postoperative recurrence. The optimal cutoff value of preoperative SCC-Ag concentrations that predicted recurrence of ESCC was 1.1ng/ml, illuminating the utility of serum SCC-Ag concentrations as an easily measurable tool for selecting a perioperative management strategy.

Dendritic core-shell rhodium@platinum-cobalt nanocrystals for ultrasensitive electrochemical immunoassay of squamous cell carcinoma antigen

Squamous cell carcinoma antigen (SCCA) has great diagnostic values for its high specificity (90–96%) in diagnosis of squamous cell carcinoma especially cancers, where electrochemical immunoassay is powerful for its accurate and reliable detection of specific tumor biomarkers at very low levels. In this work, well-defined three-dimensional dendritic core-shell rhodium@platinum-cobalt nanocrystals (Rh@PtCo NCs) were facilely prepared via a simple one-pot solvothermal strategy. Taking advantage of dramatically enhanced catalytic activity of the Rh@PtCo NCs for catechol oxidation, a label-free electrochemical immunosensor was developed for highly sensitive assay of SCCA. Under optimal conditions, the electrochemical signals were linearly correlated with the logarithm of the SCCA concentration, showing a broad linear range from 0.0001 to 10.0 ng mL−1 and a ultralow detection limit of 0.04 pg mL−1 (S/N = 3). The resultant immunosensor was further exploited for actual analysis of serum samples with convinced results. This immunosensor has good expectation in actual samples analysis and provides a universal approach for detection of other tumor markers and disease surveillance.

Squamous cell carcinoma antigen concentration in fine needle aspiration samples: A new method to detect cervical lymph node metastases of head and neck squamous cell carcinoma

BackgroundThe purpose of this study was to determine the additional diagnostic value of squamous cell carcinoma antigen (SCC‐Ag) in cervical lymph node fine needle aspiration (FNA) samples for the detection of regional metastases of head and neck squamous cell carcinoma (HNSCC).MethodsIn 149 FNA samples of 114 patients, SCC‐Ag concentration was retrospectively analyzed and associated with diagnosis to establish a cutoff concentration in relation to sensitivity and specificity of HNSCC detection.ResultsSCC‐Ag was elevated in lymph nodes from patients with HNSCC compared to lymph nodes from other patients (P < 0.01). With 0.3 μg/L as the cutoff concentration, SCC‐Ag has 96% sensitivity for detecting HNSCC.ConclusionsSCC‐Ag in FNA is a reliable test for detecting HNSCC in cervical lymph nodes.

Facile fabrication of visible light photoelectrochemical immunosensor for SCCA detection based on BiOBr/Bi2S3 heterostructures via self-sacrificial synthesis method

A novel visible light photoelectrochemical immunosensor based on BiOBr/Bi2S3 heterostructures was fabricated to detect squamous cell carcinoma antigen (SCCA). Bi2S3 nanoparticles formed on the BiOBr microflowers by the self-sacrificial synthesis method based on the facile reaction between BiOBr and S2- ions. The BiOBr/Bi2S3 composites exhibited excellent visible light photoelectrochemical activity, when ascorbic acid (AA) was employed as a perfect electron donor. The photocurrent intensity of BiOBr/Bi2S3 modified ITO electrode arrived at around 20 µA, which was approximately 30 times than that of pure BiOBr. Dopamine formed easily polydopamine film via self-polymerization on the surface of BiOBr/Bi2S3 composites to immobilize SCCA antibody. Under the optimal condition, this photoelectrochemical immunosensor realized the ultrasensitive determination of SCCA. With the logarithm of SCCA concentration in the range of 0.001–75 ng mL−1, the specific binding between SCCA and antibody led to the linearly decrease of photocurrent signal with a low detection limit of 0.3 pg mL−1 (S/N = 3). This facilely constructed photoelectrochemical immunosensor maybe have promising practical application in photocatalysis, analytical detection and biosensor, etc.

Prognostic value of C-reactive protein/albumin ratio in predicting overall survival of Chinese cervical cancer patients overall survival: comparison among various inflammation based factors.

Background: Many studies have shown the prognostic value of inflammation based factors in different cancers. This work aimed to explore the prognostic value of pretreatment C-reactive protein/albumin (CRP/Alb) ratio in patients with cervical cancer, and compared to other inflammatory prognostic factors, such as neutrophil/lymphocyte ratio(NLR), Glasgow prognostic score (mGPS), prognostic index (PI), platelet/lymphocyte ratio (PLR), prognostic nutritional index (PNI), clinicopathological parameter and squamous cell carcinoma antigen (SCC-Ag).Methods: This study was a retrospective analysis of the data related to 229 patients with newly diagnosed cervical cancer. The potential prognostic factors were evaluated by univariate and multivariate survival analysis. The correlation between CRP/Alb ratio and other prognostic factors were analyzed by Chi-Square or Fisher's exact test.Results: Multivariate analyses showed that CRP/Alb ratio was an independent predictor of overall survival (OS) in cervical squamous cell carcinoma (SCC) (HR, hazard ratio = 2.529; p = 0.045), but not in all cases of cervical cancer. However, NLR was a prognostic factor in the whole cervical cancer (HR = 2.47; p = 0.020) as well as in SCC subgroup (HR = 2.28; p = 0.038). Spearman's rank correlation analysis revealed that NLR showed a positive correlation with CRP/Alb ratio (p < 0.001). The combined index of NLR and CRP/Alb ratio could enhance the prognostic value compared to NLR or CRP/Alb ratio alone. Moreover, a high CRP/Alb ratio > 0.022 was associated with older patients (p < 0.001) and more advanced International Federation of Gynecology and Obstetrics (FIGO) stages (p < 0.001). In addition, NLR and CRP/Alb ratio were associated with SCC-Ag concentration in SCC. Furthermore, CRP/Alb ratio was a superior prognosis factor than mGPS, PI, PLR and PNI in SCC. Moreover, positive correlation was present among SCC-Ag, NLR and CRP/Alb ratio.Conclusions: CRP/Alb ratio might be considered as a novel prognosis factor and combined with NLR could improve the accuracy of OS prediction in patients with cervical cancer as well as its most common histological SCC subtypes.

Existence of a squamous cell carcinoma antigen-immunoglobulin complex causes a deviation between squamous cell carcinoma antigen concentrations determined using two different immunoassays: first report of squamous cell carcinoma antigen coupling with immunoglobulin A.

Background Squamous cell carcinoma antigen is used as a tumour marker and is routinely measured in clinical laboratories. We validated two different immunoassays and found three cases in which the squamous cell carcinoma antigen concentrations deviated greatly between the two immunoassays. Here, we aimed to elucidate the mechanisms responsible for these deviations. Methods The squamous cell carcinoma antigen concentrations were determined using the ARCHITECT SCC (CLIA method) and the ST AIA-PACK SCC (FEIA method). We performed polyethylene glycol precipitation and size exclusion chromatography to assess the molecular weight and spike recovery and absorption tests to examine the presence of an autoantibody. Results Both methods exhibited good performances for the measurement of squamous cell carcinoma antigen, although a correlation test showed large differences in the squamous cell carcinoma antigen concentrations measured using the two methods in three cases. The results of polyethylene glycol treatment and size exclusion chromatography indicated the existence of a large molecular weight squamous cell carcinoma antigen in these three cases. The spike recovery tests suggested the possible presence of an autoantibody against squamous cell carcinoma antigen. Moreover, the absorption test revealed that large squamous cell carcinoma antigen complexes were formed by the association of squamous cell carcinoma antigen with IgG in two cases and with both IgG and IgA in one case. Conclusions This study describes the existence of large molecular weight squamous cell carcinoma antigen that has complexed with immunoglobulin in the serum samples. The reason for the deviations between the two immunoassays might be due to differences of their reactivities against the squamous cell carcinoma antigen immune complexes with their autoantibody. To our knowledge, this is the first report to describe the coupling of squamous cell carcinoma antigen with IgA.

An “in-electrode”-type immunosensing strategy for the detection of squamous cell carcinoma antigen based on electrochemiluminescent AuNPs/g-C3N4 nanocomposites

A novel “in-electrode”-type electrochemiluminescence (ECL) immunosensor for the sensitive detection of squamous cell carcinoma antigen (SCCA) was constructed using magnetic graphene oxide (nanoFe3O4@GO) and Au nanoparticles/graphitic-phase carbon nitride (AuNPs/g-C3N4). The capture probe was prepared by immobilizing the primary antibody of SCCA (Ab1) on the nanoFe3O4@GO, while the AuNPs/g-C3N4 nanocomposites labelled the secondary antibody of SCCA (Ab2), which acted as a signal tag. The recognition scaffold was the following: the capture probe was immobilized onto the magnetic electrode surface that caught the target SCCA and finally allowed the immobilization of the signal tag via the interaction between antigen and antibody. Importantly, a high ECL signal could be obtained due to the unique immunocomplex, which ensured all of the g-C3N4 on the outmost plane were directly fixed onto the electrode surface and became part of the electrode surface. This resulted in an enhanced efficiency of the g-C3N4 for electrochemical luminescence, thus extending the outer Helmholtz plane (OHP) of the proposed electrode and leading to high sensitivity. Taking advantage of both nanoFe3O4@GO and AuNPs/g-C3N4, the ECL intensity was found to increase logarithmically with SCCA concentration in a wide linear range from 0.001 to 10ng/mL and with a detection limit of 0.4pg/mL. The proposed “in-electrode”-type ECL immunosensor was used to analyse SCCA in human serum, and satisfactory recoveries were obtained, indicating that the proposed method was promising for practical applications in the clinical diagnosis of SCCA.

Ultrasensitive and visual detection of squamous cell carcinoma antigen based on a silver-enhanced sandwich immunoassay using AuNPs@g-C3N4 nanocomposites

Based on gold label silver stain (GLSS) method, a sandwich-type immunoassay for visual, ultrasensitive and specific detection of squamous cell carcinoma antigen (SCCA) was constructed using gold nanoparticles@graphite- like carbon nitride (AuNPs@g-C3N4). In this assay, the capture SCCA antibody (Ab1) was immobilized on the silanized slides via the Schiff’s base links, and the AuNPs@g-C3N4 nanocomposite labeled by the detection SCCA antibody (Ab2) acted as the signal probe. The detection mechanism was as follows: Ab1 was immobilized onto the silanized slides in order to catch the target antigen SCCA, and then allowed the immobilization of the signal probe (Ab2) via the interaction between antigen and antibody. Compared with conventional GLSS method in which AuNPs are directly immobilized on Ab2, much more AuNPs corresponded to the antigen SCCA through AuNPs@g-C3N4 because g-C3N4 possessed larger surface area and loaded much more AuNPs than Ab2. Therefore, more AuNPs were exposed to silver ions during staining, more silver ions were reduced, and the sensitivity improved 1000-fold. The average grey values were linearly related to the logarithm of SCCA concentration from 0.001ng/mL to 100ng/mL, with high specificity, good reproducibility and long-term stability. Results suggested that the proposed sandwich immunoassay based on GLSS method is a simple, sensitive, selective, and visual tool for the detection of SCCA.

An ultrasensitive label-free immunosensor based on CdS sensitized Fe-TiO2 with high visible-light photoelectrochemical activity.

An ultrasensitive label-free immunosensor was developed for the detection of squamous cell carcinoma antigen (SCCA) based on CdS sensitized Fe-TiO2 nanocomposites with high visible-light photoelectrochemical (PEC) activity. In this protocol, ascorbic acid was used as an efficient electron donor for scavenging photogenerated holes. The Fe-doped TiO2 improved the absorption of TiO2 in the visible light region and promoted the photocurrent production distinctly. Especially, 0.1% Fe-TiO2 showed the highest photocurrent, which was 7.4 times that of pure TiO2. Carboxyl functionalized CdS nanoparticles (CdS NPs) were bonded onto Fe-TiO2 composite through interactions between carboxyl groups and TiO2, which further enhanced the PEC signal strength by approximately 2.9 fold compared with 0.1% Fe-TiO2. The specific binding between SCCA and antibody resulted in a decrease in photocurrent intensity and the intensity decreased linearly with the logarithm of SCCA concentration in the range of 0.001-75 ng mL(-1) with a detection limit of 0.22 pg mL(-1). The developed CdS enhanced Fe-TiO2 PEC immunosensor exhibited high sensitivity, good reproducibility, and low cost, which may have potential applications in clinical diagnosis of cancers, aptasensors, photocatalysis, and other related fields.

Ultrasensitive enzyme-free immunoassay for squamous cell carcinoma antigen using carbon supported Pd–Au as electrocatalytic labels

A novel nonenzymatic sandwich-type electrochemical immunosensor has been developed to detect squamous cell carcinoma antigen (SCCA). Nitrogen-doped graphene sheet (N-GS) was used to increase capacity of capturing primary antibodies (Ab1). Carbon-supported Pd–Au binary nanoparticles (Pd–Au/C) were synthesized and used to label secondary antibodies (Ab2). The specific binding of SCCA and antibodies enabled a quantitative attachment of Pd–Au/C on the electrode surface. Electrocatalytic analysis showed that the prepared Pd–Au/C exhibit excellent electrocatalytic activity towards hydrogen peroxide (H2O2). We use current response of electrocatalytic labels Pd–Au/C to detect the concentration of SCCA. The unique nonenzymatic immunosensor exhibits a relatively wide linear range from 0.005 to 2ngmL−1 and high sensitivity with a low detection limit of 1.7pgmL−1. The immunsensor also shows good reproducibility (4.2%) and stability (5.8%), which makes it an enormous application prospect in clinical research.

A novel immunosensor for squamous cell carcinoma antigen determination based on CdTe@Carbon dots nanocomposite electrochemiluminescence resonance energy transfer

A novel immunosensor for the detection of squamous cell carcinoma antigen (SCCA) based on magnetic nanoparticles and electrochemiluminescence resonance energy transfer in CdTe@Carbon dots (CdTe@CDs) is presented. First, Fe3O4 magnetic nanoparticles were synthesized as a solid support for the primary antibody. A sandwich-type immunoassay was performed on a magnetic force controlled carbon paste electrode via immunoreaction among the CdTe@CDs-labeled secondary antibody, SCCA, and primary antibody on the surface of the magnetic nanoparticles. A CdTe@CDs on the CdTe@CDs-labeled secondary antibody generated luminescence upon electrochemical oxidation, and great signal amplification was achieved because the CDs transferred energy to CdTe. The system was optimized to realize reliable determination of SCCA concentration within the range 0.02–12ng/mL with a detection limit of 6.3fg/mL (S/N=3).