Fast Screening of Whole Blood and Tumor Tissue for Bladder Cancer Biomarkers Using Stochastic Needle Sensors

Abstract

Bladder cancer is one of the most common urologic malignancies, which is more frequent in men than in women. The early diagnosis for this type of cancer still remains a challenge, therefore, the development of a fast screening test for whole blood and tumor tissue samples may save lives. Four biomarkers, p53, E-cadherin, bladder tumor antigen (BTA), and hyaluronic acid were considered for the screening tests using stochastic needle sensors. Three stochastic needle sensors, based on graphite powder and modified with three types of chitosan, were designed and characterized for the screening test. The proposed sensors showed low limits of quantification, and high sensitivity and selectivity levels. The recoveries of p53, E-cadherin, BTA, and hyaluronic acid in whole blood samples and tissue samples were higher than 95.00% with a relative standard deviation lower than 1.00%.

Stochastic biosensors based on N- and S-doped graphene for the enantioanalysis of aspartic acid in biological samples

“…During the pattern recognition phase, also known as the rst phase, the enantiomers are extracted into the channel, blocking it, the intensity of the current drops to zero until the whole molecules enter the channel; the time spent at this phase is known as t off and represents the signature of the analyte; its value is used for the qualitative analysis of the enantiomers. The binding phase, also known as the second phase, [18][19][20] takes place when the analytes of interest interact with the wall channel and redox processes take place.…”

“…17 To date, stochastic sensors have been used for the early diagnosis of different types of diseases, such as diabetes. [18][19][20] The response of the stochastic sensors is based on the channel conductivity: the rst stage is the one in which the molecule enters the channel, and the current drops to zero (qualitative analysis is performed during this stage, the measured t off value being known as the signature of the analyte); during the second stage, redox and binding processes take place inside the channel (the measured value of t on is correlated with the concentration of the analyte). The advantages of using the stochastic sensors versus other electrochemical sensors are: they can perform a reliable qualitative analysis by being able to identify specic analytes, and even enantiomers; the quantitative analysis is also reliable, the quantication being performed inside the channel found in the powders used for the design of the sensor.…”

“…The advantages of using the stochastic sensors versus other electrochemical sensors are: they can perform a reliable qualitative analysis by being able to identify specic analytes, and even enantiomers; the quantitative analysis is also reliable, the quantication being performed inside the channel found in the powders used for the design of the sensor. [18][19][20] In this paper, two stochastic biosensors based on a-hemolysin and hemin, immobilized in an exfoliated graphene doped with nitrogen and sulphur were proposed for the enantioanalysis of aspartic acid in biological samples: whole blood, urine, saliva, and tissue. The selection of a-hemolysin and hemin for the design of the stochastic sensors is due to the structures of ahemolysin and hemin; a-hemolysin and hemin present the necessary pores needed for obtaining the stochastic sensing.…”

Stochastic Microsensors Based on Carbon Nanotubes for Molecular Recognition of the Isocitrate Dehydrogenases 1 and 2

“…To address the necessities of clinical practice for the molecular recognition and determination of IDH1 and IDH2 in biological samples, we developed a reliable, fast, and cost-effective screening method based on the utilization of stochastic microsensors-the only type of sensors able to perform qualitative and quantitative analysis [13][14][15]. The stochastic microsensors were based on immobilization of a solution of PIX in SWCNT and MWCNT decorated with Cu and Au nanoparticles.…”

Sensitive Detection of Heregulin-α from Biological Samples Using a Disposable Stochastic Sensor Based on Plasma Deposition of GNPs–AgPs’ Nanofilms on Silk

“…Stochastic sensors are very good alternatives to classical electrochemical sensors, as they are able to make reliable qualitative and quantitative analyses [ 8 ]. To date, they were successfully used for biomedical analysis [ 9 , 10 , 11 , 12 ]. The principle of stochastic sensors is based on current conductivity.…”