FIELD OF INVENTION

The present invention relates to the field of early detection of cancer.

BACKGROUND OF THE INVENTION

The detection of cancer in its early stage of asymptomatic patients before the onset of metastasis is the most important objective in cancer research. It has already been reported and found that early detection lead to improvement in cancer patients with better prognosis. Though there are many blood-based biomarkers diagnosis procedures are routinely used in clinical practice for cancer detection and risk stratification. Despite of huge intellectual and financial involvement worldwide, there is no prevailing biomarker, which is suitable for early diagnosis of cancer. Till date, several methods have been developed for detection of cancer, but none of them is suitable for early detection. Therefore, there was a long standing and unmet need for an in-situ detection of the cancer cell.
SUMMARY OF THE INVENTION
The present invention provides a solution to the problems associated with early detection of cancer by a developing a sensor with specific aptamer which can be used in a method for early detection of cancers. In one of the embodiments of present application is a real time method for the in-situ detection of cancer at an early stage comprising of: i) collecting sample cells; ii) incubating aptasensor with PBS at pH 7.4 and collecting spectral measurements; iii) incubating aptasensor with sample cells to be analysed and collecting spectral measurements; iv) monitoring the spectral changes obtained by replacement of PBS with sample and calculating different

critical values; and v) providing the result after analysing the different critical values obtained in step iv).
In another embodiment, the invention provides a method for in-situ detection of cancer at an early stage, wherein the spectral measurements were carried out using a variable angle spectroscopic ellipsometer (VASE) at an angle of incidence of 68° in the spectral range 350-1050 nm.
In another embodiment, the invention provides a method for in-situ detection of cancer at an early stage, wherein the in-situ detection of the cancer cell is based on selective binding of the cancer cells on the aptasensor.
In another embodiment, the invention provides a method for in-situ detection of cancer at an early stage, wherein the method is label free.
In still another embodiment, the invention provides a method for in-situ detection of cancer at an early stage, wherein the critical values comprise of changes of delta and psi value in presence and absence of the specific cells with respect to time.
In still another embodiment, the invention provides a method for in-situ detection of cancer at an early stage, wherein the polarization change is represented as an amplitude ratio (*F) and the phase difference (A).

In another embodiment, the invention provides a sensor with smart zipper nanoarchitecture for detecting cancer cells comprising of a specific aptamer capable of interacting with cancer cells.
In another embodiment, the invention provides a sensor capable of real time and label free monitoring of cancer cells.
In another embodiment, the invention provides a sensor having a temperature dependent capture and release property.
In another embodiment, the invention provides a sensor used with variable angle spectroscopic ellipsometry.
In another embodiment, the invention provides a sensor capable of capturing and releasing the target cell through a non-enzymatic and mechano-thermal procedure.
In another embodiment, the invention provides a sensor functional at a temperature range of 20 -37°C.
In another embodiment, the invention provides a sensor, wherein the sensor is a gold surface immobilized aptamer.
Other aspects and salient features of the invention will be apparent to those skilled in the art from the detailed description taken in conjunction with the accompanying drawings of the present application.

DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: The basic backbones of design of the sensor
Figure 2: The basic description of in situ flow set up
Figure 3: Changes of delta and psi value in presence and absence of the specific cells with respect to time.
Figure 4: Psi vs. wavelength at 20°, 40°, and 60°. The red curves correspond to the sample, the pink curves correspond to the reference.
Figure 5: Delta vs. wavelength at 20°, 40°, and 60°. The green curves correspond to the sample, the blue curves correspond to the reference.
Figure 6: Delta & Psi vs. angle of incidence at 450nm. The red and green curves correspond to the sample, the pink and blue curves correspond to the reference.
DETAILED DESCRIPTION
The various features with reference to the non-limiting embodiments and those illustrated by the accompanying drawings are explained herein in the following description. Descriptions of well-known components and process techniques are omitted so as not to unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments

described herein. Accordingly, the examples should not be construed as limiting the scope of the invention described herein.
The present application discloses a novel label free real time method for the detection of cancer at an early stage. An elhpsometry based aptasensor has been designed with the help of nanotechnology to capture the cancer cells by the specific aptamer with a flow condition mimicking blood and their real time label free monitoring by the variable angle spectroscopic ellipsometry. The smart aptasensor equipped with zipper architecture enable us to capture the target cell and release through a non-enzymatic and mechano-thermal procedure with the most biocompatible temperature range 20 -37°C for in depth analysis and diagnosis of the captured cancer cells by clinical procedure. The smart zipper nanoarchitecture with temperature dependent capture and release property of the sensor is composed of aptamer linked to gold surface and the polymer is zipped with gold nanoparticles embedded.
Construction of sensor
A sensor with smart zipper nanoarchitecture for real time and label free detection and monitoring of cancer cells is developed using specific aptamer capable of interacting with cancer cells. The sensor uses variable angle spectroscopic ellipsometry for the detection. The sensor having a temperature dependent capture and release property is highly useful to develop a method and system capable of capturing and releasing the target cell through a non-enzymatic and mechano-thermal procedure. The sensor is functional in a temperature range of 20 -37°C. Cancer specific sensors are

developed by immobilizing the aptamer on a gold surface or other suitable materials.
Method for early detection of cancer
The early detection of cancer uses in-situ measurements using a variable angle spectroscopic ellipsometer (VASE) at an angle of incidence of 68° in the spectral range 350-1050 nm. The method uses a glass cell with a magnetic stirrer and a flow system for simulating the blood flow as shown in Figure 2 is used. The sensor is first incubated in PBS at pH 7.4 and spectral measurements are carried out without cells. Subsequently, sample to be analysed is added and the corresponding spectral changes have been monitored. A negative control has been kept for each individual set of experiment.
The in-situ detection of the cancer cell is based on selective binding of the cancer cells on the aptasensor and their corresponding label free detection. Figure 3 shows the changes of delta and psi value in presence and absence of the specific cells with respect to time.The polarization change is represented as an amplitude ratio, *F, and the phase difference, A.
The foregoing description completely discloses the general nature of the embodiment/aspect claimed herein that others can, by applying current knowledge, readily modify and/or adapt for various applications and such specific embodiments without departing from the generic concept, and therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed

embodiment. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not for limitation.

WE CLAIM

A real time method for the in-situ detection of cancer at an early stage comprising of:
i. collecting sample cells;
ii. incubating aptasensor with PBS at pH 7.4 and collecting spectral measurements;
iii. incubating aptasensor with sample cells to be analysed and collecting spectral measurements;
iv. monitoring the spectral changes obtained by replacement of PBS with sample and calculating different critical values; and
v. providing the result after analysing the different critical values obtained in step iv).
The method as claimed in claim 1, wherein the spectral measurements were carried out using a variable angle spectroscopic elhpsometer (VASE) at an angle of incidence of 68° in the spectral range 350-1050 nm.
The method as claimed in claims 1 to 2, wherein the in-situ detection of the cancer cell is based on selective binding of the cancer cells on the aptasensor.

The method as claimed in claims 1 to 4, wherein the critical values comprise of changes of delta and psi value in presence and absence of the specific cells with respect to time.
The method as claimed in claims 1 to 5, wherein the polarization change is represented as an amplitude ratio psi (*F) and the phase difference delta (A).
A sensor with smart zipper nanoarchitecture for detecting cancer cells comprising of a specific aptamer capable of interacting with cancer cells, wherein the sensor is capable of real time and label free monitoring of cancer cells.
The sensor as claimed in claims 7 to 8, wherein the sensor is having a temperature dependent capture and release property.
The sensor as claimed in claims 7 to 9, wherein the senor is used with variable angle spectroscopic ellipsometry.
The sensor as claimed in claims 7 to 10, wherein the senor is capable of capturing and releasing the target cell through a non-enzymatic and mechano-thermal procedure.
The sensor as claimed in claims 7 to 12, wherein the sensor is a gold surface immobilized aptamer.