Pristine graphene based biosensor for biomarker detection and related core particles, materials compositions methods and systems

A multiplex graphene biosensor, comprising:

• a graphene core particle and a plurality of target specific detectable components attached to the graphene core particle,
• wherein the graphene core particle comprises
• at least two pristine graphene nanosheets having a pristine graphene nanosheet surface stacked over one another to form a pristine graphene aggregate, and
• a coating layer covering at least 50% of a pristine graphene nanosheet surface,
• said coating layer comprising an organic and/or inorganic compound, wherein the organic and/or inorganic compound has a solubility in water of at least 10 grams per liter H2O at 25 degrees C. and is able to be covalently linked to, or in water electrostatically stably attached to, pristine graphene,
• wherein the organic and/or inorganic compound is attached to a pristine graphene nanosheet to form said coating layer,
• wherein the pristine graphene of the at least two pristine graphene nanosheets has a carbon content of at least 99%, an oxygen content of less than 1% and is pure, such that the pristine graphene is free of foreign substances and impurities,
• wherein the pristine graphene nanosheet and/or the organic and/or inorganic compound of the coating layer is configured to present a functional group capable of binding a corresponding functional group in an aqueous solution;
• wherein each target specific detectable component is formed by a detectable moiety capable of emitting a fluorescent signal, the detectable moiety attached to a peptide linkage comprising a recognition sequence specific for a target biomarker,
• wherein in each target specific detectable component the peptide linkage is configured to provide in combination with the coating layer of the graphene core particle, a quenching distance between the detectable moiety and the graphene core particle, wherein the graphene nanosheet quenches the fluorescent signal of the detectable moiety, and
• wherein the recognition sequence for the target biomarker of each detectable component is configured to specifically detect a target biomarker and the plurality of detectable components is selected to specifically detect a plurality of different target biomarkers.

A system for multiplexed detection of the activity of a plurality of biomarkers in a biological sample, the system comprising

• a multiplex graphene biosensor and/or a graphene biosensor each comprising a graphene core particle presenting a peptide linkage specific for one biomarker of the plurality of the biomarkers
• wherein the graphene core particle comprises
• at least two pristine graphene nanosheets having a pristine graphene nanosheet surface stacked over one another to form a pristine graphene aggregate, and a coating layer covering at least 50% of a pristine graphene nanosheet surface, said coating layer comprising an organic and/or inorganic compound,
• wherein in the graphene core particle
• (i) the organic and/or inorganic compound has a solubility in water of at least 10 grams per liter H2O at 25 degrees centigrade and is able to be covalently linked to or in water electrostatically stably attached to pristine graphene,
• (ii) the organic and/or inorganic compound is attached to a pristine graphene nanosheet to form said coating layer,
• (iii) the pristine graphene of the at least two pristine graphene nanosheets has a carbon content of at least 99%, an oxygen content of less than 1% and is pure, such that the pristine graphene is free of foreign substances and impurities, and
• (iv) the pristine graphene nanosheet and/or the organic and/or inorganic compound of the coating layer is configured to present a functional group capable of binding a corresponding functional group in an aqueous solution,
• wherein the graphene multiple biosensors further comprise a plurality of target specific detectable components attached to the graphene core particle, in which
• each target specific detectable component is formed by a detectable moiety capable of emitting a fluorescent signal, the detectable moiety attached to a peptide linkage comprising a recognition sequence specific for a target biomarker,
• the peptide linkage of each target specific detectable component is configured to provide in combination with the coating layer of the graphene core particle, a quenching distance between the detectable moiety and the graphene core particle, wherein the graphene nanosheet quenches the fluorescent signal of the detectable moiety, and
• the recognition sequence for the target biomarker of each detectable component is configured to specifically detect a target biomarker and the plurality of detectable components is selected to specifically detect a plurality of different target biomarkers,
• and wherein each graphene biosensor further comprises:
• a detectable moiety capable of emitting a fluorescent signal, the detectable moiety covalently bonded to the graphene core particle through a peptide linkage comprising a recognition sequence specific for the target biomarker, in which the coating layer and the peptide linkage are configured to set a quenching distance between the graphene nanosheets and the detectable moiety in which the graphene nanosheets quench the fluorescent signal of the detectable moiety,
• the peptide linkage is further configured to set, upon recognition by the target biomarker of the recognition sequence, an emitting distance between the graphene nanosheets and the detectable moiety wherein the graphene nanosheets do not quench the fluorescent signal of the detectable moiety, and
• the peptide linkage and the detectable moiety thus form a target specific detectable component configured to emit a detectable fluorescent signal upon modification of the peptide linkage by the target biomarker.